Few, if any , formations in Epic-A do well standing on their own. Go against a player that uses any kind of Combined Arms tactics and even the best formation is doomed.
As to Genestealers and Lictors.
Genestealers make good flank guards when there is cover available. Are good at forming an area defense behind swarms to prevent those nasty Teleports and deep strikes. And make a great trip wire force to block FF assaults from slaming your swarm hard. In all the above cases they are operating close to much bigger friends.
Lictors earn their points in twoways. When not on the table an opponent tends to look for what they can do in the next phase, and are nervous about broken formations moving too far from non-broken friends. They are best deployed in cover or near covering terrain where the enemy cannot open up on them right away with direct fire. This forces the opponent to react to them or pay a heavy price for ignoring them.
They love to eat broken formations...........
One thing about "Getting your points worth". Sometimes, like Sentinel Walkers, it isn't what they destroy but more what they do that earns them their points. Doing that is up to the player and not the designer.
All of them are worth their points IF one uses them right.
Jaldon
