I must disagree Ginger. By implication that would mean that the Hive Mind doesn't understand the instincts of the creatures it both controls and creates. I my opinion it not only understands the instinctive behaviour of the creatures it creates and controls, but it exploits these behaviours to make it easier for it to exert control.
For example a Dactylis, Exocrine or a Biovore's insticntive behaviour would be more like 'nesting' behaviour in the old Titanicus lingo. Under your definition the Hive Mind assumes all of its creations want to physically contact the enemy to destroy them. Therefore why would the Hive Mind create creatures that do not have this type of instictive behaviour? I my opinion it wouldn't.
The Orks are an entirely different ball of wax, but make a good comparison race to show those differences. Some Orks love to get in close and have a good punch up with the enemy. Some Orks love to go fast so they can get in close with the enemy even faster then the rest of the Boyz and have a good punch up. Some Orks love to go fast and love the sound of their gunz going dakka dakka, but they want to get close enough to appreciate the mayhem they are causing. Some Orks just love the sound of their gunz going dakka, dakka, but they to want to get close enough to appreciate the mayhem their gunz are causing. Some Orks like really really big gunz and love to see the big holes and the explosion created by that really really big gun, and the closer they are to the impact craters the more they like it. It could be said, with some accuracy, that the Orks as a race are a bit unhinged in the head because of their love of both war and mayhem. In fact they take it too the extreme of constantly living on a war footing, if not with someone else then with each other.
Therefore, for the Orks to have special rules that reward them for getting at closer to the enemy follows with their natural instincts. Their leaders even think this way making the entire issue of special rules to crerate this feel even more accurate.While it is true the majority of the Nid army is made up of troop types whose natural instinct is to get real close and devour the enemy, they do it for a far different reason. Orks, despite being insane by human standards, are thinking creatures. Nid non-synapse creatures aren't really thinking creatures, in fact it is doubtful they are even self-aware. While all Orks gravitate toward close action with the enemy they do it because they enjoy it. The Nids don't have the concept of enjoyment, even up to the Hive Mind itself, they do what they do without giving it any thought as to why they are doing it. And not all Nids are designed to carry out what they do in war in close combat. While an Ork may have a weapon with ten times the range of a bolter, and he will open fire with it as soon as he possibly can, that same Ork still wants to get closer so he can better experience the mayhem his weapon is creating. The same is not true for the Nids. A Nid creature with a weapon ten times the range of a bolter has only one desire; to destroy the enemy using its primary weapon. The range at which it uses that weapon has no meaning to the creature itself, so long as the enemy is in range to be attacked it attacks them, it has no desire to close the range to experience the destruction it is causing. In fact it has no real desires at all. There is little doubt that the Hive Mind takes full advantage of the instictive, and mindless, behaviour of the troops it controls. In fact it makes their entire command and control system possible. The Hive Mind simply has to place a creature in a position on the battlefield where its instictive behaviour can take over and do the rest.
To give the Nids a 'bonus' for engage actions would be to lump the entire Nid Army into the same mold as Orks, which they are not. Yes a majority of Nid creatures are designed for close combat action, but not all of them. Further, there is no 'army wide' Nid desire to get into close combat action with the enemy, in fact the entire Nid army has no real 'desires' at all except to continue to devour and expand. Giving the Nid Army a 1+ initiative reflects well the Hive Minds strong ability to control the troops under its command, and its ability to exploit each of the troops instinctive behaviour. In other words to direct those creatures into an area where their instinctive behaviour will do the most good, for Nid expansion that is.
A good example of how the Nid army functions would be to describe the Hive Mind as being intuitive rather then instinctive or rational. As long as the Hive Mind is in control of things everything runs like clock work and without a hitch. On the battlefield the Hive Mind will have little trouble controlling its minions as long as it is doing the attacking, is in control of the initiative (In military terms not game terms), and the enemy is constantly re-acting to Nid moves instead of acting against Nid moves. Being intuitive means that when the Nid army is forced to react (defend against an enemy move) its reaction should be sluggish or awkword (Not ineffective so much as diminishing in returns the more often the Nids have to do it). Being intuitive also means that the when things start to fall apart on the battlefield the Nids will have a hard time getting their feet back under themselves.
The intent is that with a 1+ initiative the Hive Mind will have excellent control over the instinctive behaviour of all its minions. I have found this to be true of SM armies with 1+ initiative, IE excellant control. BUT without the SM special rules for BMs the Nid army should start to have problems with control, both directly and indirectly. Add in the lower spawning rates in the present lists, no cross spawning into differnt swarms, and with the elimination of the merging rule and the Nid command structure could quickly fall apart. In effect, in game terms and in broad terms, as long as the Nids are dictating the action on the battlefield they should thrive (Attacking instead of reacting). But if the situation starts to turn against them then it should progressively fall apart around their ears. This would be a vastly different Horde Type Army then the Orks despite having the same basic concept driving them. Basically I have seen Ork armies recover from battles where their offensive power was pretty much in the tank on turn two, and they turned it around quickly in turn three. I want the Nids to either keep the pressure on from turn one on, or fall apart if they fail to do so.Back to 'historical' references. In every account I have read the Nids always do well as long as they are dictating what happens on the battlefield, but their ability to maintain the fight degrades quickly when the enemy is dictating the fight. I am trying to re-create in Epic-A this same type of situation.
Whew that was long..................
Cheers All,
Jaldon