This is a report on a first test game. I've spent enough time here to pick up a few things but it's still my first proper game. My opponent is more familiar with 40k and shows it in the army selection, also his first game. As 1 major error was made with ATSKNF you can decide on the validity of the final result (We're considering it a test game for that reason).

Things to look at are individual formation performances and how a 40k player approaches and plays an E:A SM force (He recognised afterwards that it was a sub-par list and it very much is not 40k). The ATSKNF error amounted to not counting hackdown hits from combat resolution as half which affected 3 engage actions (noted in the report and would have reduced formation annihilation to formation mauling and breaking). Of course there is also the possibility of other errors.

I made the Tyranid list first (and a back up Eldar list) and my opponent had free choice of SM, Squat, Ork, Eldar, Tyranid and Titan Legion forces. Comfortable with 40k SM he chose them and made a list before I revealed my list (So both players picked and built a list blind). We both had a look at each others lists and he thought the SM were in trouble from the start.

Tyranids - 9.2.1
Modifications - Ravener CC reduced from 3+ to 4+ and Gaunts count half casualties in combat rounded up instead of down.

2 Hierophants - 550
Harridan - 175
Genestealers - 175

Synapse Node - 125
Assault Group - 125
+ Hive Tyrant - 50
Assault Group - 125
Assault Group - 125
Attack Group (Winged) - 100
Hive Tyrant (Winged) - 100

2 Ravener Clusters - 250
2 Gargoyle Clusters - 200
4 Gaunt Cluster (2T/2H) - 300

Bio-Artillery Cluster (2 Dactylis) - 150
Assault Spawn Cluster (3 Haruspex) - 175
Assault Spawn Cluster (3 Malefactor) - 175
Carnifex Cluster - 125

Total - 3000

Synapse Swarm Compositions
Blitz Guard - (Synapse Node, 2 Dactylis, 2 Gargoyles)

Attack Swarm - (2 Hive Tyrants (Winged), 3 Haruspex, 1 Malefactor)

Assault Swarm 1 - (Hive Tyrant, 2 Warriors, 3 Carnifex, 2 Raveners, 2 Gargoyles, 2 Termagants, 2 Hormagaunts)

Assault Swarm 2 - (3 Warriors, 2 Raveners, 2 Malefactor, 2 Gargoyles, 2 Hormagaunts, 2 Termagants)

Assault Swarm 3 - (3 Warriors, 4 Raveners, 2 Gargoyles, 4 Termagants, 4 Hormagaunts)

Space Marine Army with NetEA mods

Devastators - 250
+ Supreme Commander - 100
+ 2 Dreadnoughts (Las) - 100
Thunderhawk - 200
Assault 1 - 175
Assault 2 - 175
Land Raiders - 350
Whirlwinds - 300
Landspeeders 1 - 200
Landspeeders 2 (4x Tornadoes) - 240
Warhound 1 - 275
Warhound 2 - 275
Terminators - 350
- 2990

SM wins deployment roll and chooses corners. That leaves a fairly open killing ground with a high number of objectives that the Tyranids will have to move into and allows the SM's to concentrate on controlling that area with their higher saves and weak Tyranid ranged shooting.
Deployment as shown with the Devastators garrisoning on a forward objective and the Genestealers doing likewise.

Turn 1

Strategy Roll - SM

Assault 1 - March to closest objective
Genestealers – March to forest and threaten Whirlwinds
Land Raiders – Double on Assault Swarm 1 killing 1 Termagant
Attack Swarm – Failed activation and made a single move.
Warhound 1 – Advance on Genestealers in trees killing 2
Hierophant 1 – March
Landspeeders 2 – March to take Objective
Assault Swarm 3 – March
Whirlwinds – Sustain on Assault Swarm 3 killing 3 Termagants, 2 Raveners, 1 Hormagaunt and 1 Warrior.
Synapse Node – Failed activation, regrouped.
Landspeeders 1 – March
Assault Swarm 2 – March to threaten Devastators
Assault 2 – Don't move very far
Hierophant 2 – March
Warhound 2 – Double on Hierophant 2, -2DC
Harridan – Double on Warhound 1 removing 1 void shield
Devastators – Advance on Assault Swarm 2 killing 1 Termagant
Assault Swarm 1 – Double on Warhound 2 with no effect
Thunderhawk and Terminators – Air Assault on Synapse Node taking 1 BM for coming under fire from flak. Poor hit rolls and great Synapse Node saves meant only 1 Dactylis was killed. SM  resolution roll is poor and Tyranids roll great. Tyranids get a 9 to 3 victory. An error was made here in regard to hackdown hits and all Terminators and the Thunderhawk were removed when 1 Terminator stand should have survived broken.

Spawning – Synapse Node (Dactylis), Assault Swarm 3 (3 Termagants, 1 Hormagaunt, 1 Ravener), Assault Swarm 2 (1 Ravener), Assault Swarm 1 (2 Termagants)

Start of Turn 2 looks like this

Turn 2

Strategy Roll – SM

Whirlwinds – Sustain on Assault Swarm 1 causing no damage
Assault Swarm 2 – Engage Devastators. 2 Devastators are killed for 1 Gargoyle, 1 Termagant and 1 Hormagaunt. Another poor roll for the SM combat resolution combined with a good Tyranid roll gives the Tyranids victory 9 to 5. Again another error with Hackdown hits leads to removal of 2 Devastators and 2 Dreadnoughts when 2 stands should have survived.
Land Raiders – Sustain on Assault swarm 1 killing 1 Carnifex, 1 Termagant and 1 Gargoyle
Synapse Node – Dactylis Sustain on Landspeeders 1 killing 1 and placing 4BM for disrupt.
Warhound 2 – Sustain on Assault Swarm 1 and failing to kill anything
Attack Swarm – March again, they're taking the scenic route.
Warhound 1 – Advance on Hierophant 2 removing another 1DC
Harridan – Engage Warhound 1. Went 2 rounds with the Harridan winning the second round resolution roll and hacking down the Warhound las DC. The Harridan suffered 2DC of damage
Landspeeders 1 – Advance and fire on Assault Swarm 1 taking 1 Carnifex
Genestealers – Engage the Whirlwinds killing 1 for no casualties but tying on Combat resolution. The 2nd Round sees 2 more Whirlwinds killed for no losses and the final Whirlwind hacked down.
Landspeeders 2 – Double and fire at the Synapse Node causing no damage.
Assault Swarm 1 – Fails the activation, Regroups and spawns 1 Termagant
Assault 1 – Moves away from the Tyranid advance
Hierophant 2 – Fails activation and takes a shot at Warhound 2 dropping 1 Void shield
Assault swarm 3 – Fails activation and makes a move
Hierophant 1 – Marches to contest an objective and to put pressure on the Land Raiders and Warhound 2 next turn.

Spawning – Assault Swarm 3 (2 Gargoyles), Assault Swarm 1 (1 Ravener), Assault Swarm 2 (1 Hormagaunt)

Start of Turn 3 looks like this

Turn 3

Strategy Roll – Rare Tyranid win

Hierophant 1 – Engages Land Raiders killing 3 for no lost DC and winning 9 to 3 hacking down the last one
Warhound 2 – Sustain on Assault Swarm 1 killing 1 Hormagaunt, Tyrant and Warrior breaking the swarm
Hierophant 2 – Advances on Landspeeders 2 killing 1
Landspeeders 2 – Advance on Synapse Node causing no damage
Synapse Node – Fails activation and regroups
Landspeeders 1 – Advances on Assault Swarm 1 removing a Ravener
Harridan – Flies to capture an objective
Assault 1 – Moves back again surrendering an objective
Assault Swarm 3 – Engages Landspeeders 1 killing 2 and winning 9 to 6. Another Hackdown error, 1 Speeder should have survived.
Assault Swarm 2 – Engage Warhound 2 destroying it over 2 rounds
Genestealers – Failed activation and move towards objective

Assault Swarm 1 Rallies

Tyranids Winning 1-0 (BTS)

Start of Turn 4 looks like this

Turn 4

Bit of a forgone conclusion at this point.

Strategy – SM

Landspeeders 2 – Sustain Synapse Node causing 1DC damage
Attack Swarm – Engages Assault 2 killing them all
Assault 2 – Engages Attack Swarm, loses 3 stands but kills 3 Haruspex and a Tyrant, winning the assault and hacking down a Malefactor and Hormagaunt before breaking and running for the trees. The remaining Tyrant broken but decided to stay put.

Remaining Tyranid formations move to capture the objectives (Including a couple of inconsequential activation failures).

Final score 4-0 to Tyranids only missing the Blitz by a defiant last Assault Marine strike.

Conclusions

SM player recognised the weak list and a lack of overall strategy (and game theory such as prepping fire to give a BM) led to a poor performance. There was also some awful/great rolling leading to losses that should have been easy victories (like the Terminator and Thunderhawk assault). I also think there is a fear of engaging Tyranid Formations due to reputation more than outright ability.

The thing that I saw with the SM force was a lack of decisive firepower that could cut through the Tyranid swarms and really hurt them. The first turn damage to the Tyranid swarms was almost completely negated by spawning. Easy to see in hindsight but certainly something the SM player saw at the end, concentrate fire on a couple of targets rather than spreading fire around.

The Warhounds and Land Raiders did ok with the Whirlwinds probably the best SM formation. Also when it closed to assault the Tyranid Assault Swarms were rolling lots of dice that the SM couldn't deal with. The SM were just matching or losing on casualties caused but being outnumbered, usually by at least 2-1 and having small formation sizes that feel every lost stand really hurt. Even with the hackdown error the formations would still have been badly mauled (66%-75% losses) and broken.

On the Tyranid side the big swarms proved quite resilient. Combat was good with the fast Raveners and Hormagaunts in the Swarms getting up close to gain extra attacks and the remaining stands providing enough mediocre FF to get past the SM's good saves.
The Harridan and 2 Hierophants did well, firing was poor but the number of attacks in engagements meant they could match up to pretty much any Formation the SM's had. Vulnerable to direct fire, there just wasn't enough in the SM list to really do enough damage.
Unless engaging/rallying the Tyranids do fail a fair few activations

I get the feeling that the matchups between SM and Tyranids favours the Tyranids. SM have small formations that just don't have enough attacks to fight off larger Tyranid Swarms. The Tyranids just roll enough dice so that the SM fail saves and those small formations lose stands they can't really afford to lose.
SM lack a lot of direct firepower to really hurt Tyranid Swarms. At range they can't do enough damage to negate the 2D3 spawning rate and up close to reduce the Spawning rate they are vulnerable to the fast moving tyranid elements like Raveners, Gargoyles and Genestealers that can engage at 40cm through the Infiltrator ability.

I don't think the Marine list was a total loss however 2 assault units on the ground was always a sub optimal choice.

I'd have put them both in the thunderhawk and teleported my Terminators instead.

Yep, Another error. Warhound should have survived on 1 DC. Game has been played, a few too many errors (and probably more to find) so we've agreed that the game result shouldn't stand. Rematch will have to wait till some free time pops up though.

Opponent did like the game, particularly the turn sequence that allows reacting rather than watching for both players.

Something that came up during the game on calculating BMs on Marine formations. The +1 Combat resolution for no BMs only applies to Marine formations with no BMs not ones with 1BM halved and rounded down. How does the less BM's than the opponent work. If one formation had 1BM and the marine formation had 2BMs they'd be equal and no bonus for less BMs is given to either side. What happens if the Marine Formation had 3BMs? would the half BM that isn't there mean the Marines count as having more BM or would it still be equal?

I did go through a couple of ideas for Thunderhawk usage such as the Assault Marines or maybe Dev squad with P.Fist Dreads but the Terminators were something that surprised me and 9 times out of 10 would have won the combat. The Synapse Node formation had virtually no defensive capability to fight back and caused no hits, it was just great save rolling on the Synapse node (Saving 2MW and 2 ordinary hits) with a combined poor Terminator resolution roll and great Node resolution roll.

You round down so a marine formation with 3 BM counts as having 1 BM for comparison in the post assault phase.

A formation with 1 BM has BM's when comparing if either side has BM's, but 0 when comparing who has more.