It seems that a recurring theme from successive versions of ArmA is the lack of a functioning "suppressive fire" command for use with AI subordinates.
In the existing command menu, we do have a "suppressive fire" command, but as with ArmA2, it doesn't cause subordinates to fire suppressively at a piece of ground. Although i can't get it to work at all in the alpha, I suspect it's meant to function the same as in ArmA2 where you command "suppressive fire" against a known enemy, in the same way you'd command "engage that...." against a known enemy, the only difference between the two commands being that with "engage that", units will only shoot at the target if they can see it whereas with "suppressive fire" they'll fire at the target's last known location if they don't currently have visual contact with him - but only until their knowledge of the enemy expires (or such is my understanding anyway).
The issue here being that a unit has to have knowledge of an enemy at a location before you can get that unit to shoot there.
What I'm suggesting is that we be given the ability to command units to fire at a location/area whether or not they currently "know about" an enemy at that location. You should be able to command your squad to begin laying down fire on any area at any time, regardless of enemy being acquired there.
The reasons are simple:
In a firefight, it's perfectly reasonable for a commander to order his subordinates to fire at a piece fo ground where said subordinates don't see enemy. The contexts where this is done include, but are not limited to:
-Suppressing a *suspected* enemy location as opposed to a known one.
-Higher units or lateral units informing you of enemy at a location even if you can't see them.
-Denying ground to the enemy i.e. cutting off likely escape or reinforcement routes with fire.
-Speculative fire, or "recon by fire", engaging an area to see if you get a reaction.
-The commander knowing about an enemy at a location that the others cannot see.
(sometimes you spot an enemy, but the the behavior engine doesn't think you see him, so there's no communication of "Rifleman, 300m, bearing....", even though you're looking right at a unit)
All of these techniques are perfectly reasonable in the real world, and they involve a commander ordering subordinates to shoot at a place as opposed to a seen enemy. As such, we should have that same freedom in ArmA.
Even more importantly, the ability to fire at locations regardless of whether enemy are seen there is critical to supporting fire. Indeed, that's preciceley what supporting fire is - trying to keep an enemy's head down in order to enable another friendly element to maneuver.
Shooting only at targets you can see is not supporting fire. That's just firing at targets of opportunity, and has little suppressive value. Effective supporting fire results in not being able to see the enemy because you've forced him to keep his head down. So having units only capable of shooting at targets they can see means precisely that you have no supporting fire function in your simulation. And anything deserving of the term "infantry simulation" would have supporting fire modeled, being that it's one of the most fundamental concepts of land warfare.
I feel that the current system for controlling AI's direct fire is very convoluted and disjointed, and which is very unrealistic. In reality, all an infantry section commander really does is either points at a piece of ground (which may or may not contain a seen enemy), and says "shoot there" or "shoot those guys", or he says "Just watch out and shoot any targets that pop up", or he tells them not to shoot.*
To realistically simulate squad fire control, they should model several rates fire and use that as a basis for how the commander orders the AI to engages/fire. At the very least, the rates of fire should be should be "Slow Rate (suppressive)", "Rapid Rate (suppressive)" and "Watch and Shoot" (and of course, hold fire).
While pointing the cursor at a place on the terrain, ordering "Slow Rate" or "Rapid Rate" to your subordinates should cause them to shoot slowly or rapidly respectively (exact RPMs being open for debate) at the area you're pointing at (not unlike "fire at location" for artillery). They should fire randomly within a general area centered around the designated point (as opposed to directly at the precise point, for obvious reasons). And while they're doing that, they should be free to take aimed shots at any targets of opportunity that appear in the vicinity of their designated target area, and then go back to firing suppressively within the designated area once the target is gone, and continue to fire there until you tell them to stop. This is how section/squad fire is controlled in the real world.
Ordering "Watch and Shoot" should simply make your subordinates watch the designated area, and shoot anything that appears in front of them.
(Note: The watch and shoot *area* would want to be modeled larger than the suppressive fire area as "watch and shoot" is a speculative, "keep an eye out" kind of command, where "suppressive fire" is specifically directed at a particular place/area. This could serve as a decent analogue for assigning arcs/sectors of fire/observation to individual subordinates)
*The other thing a section commander does is he divides the ground up into "arcs" or "sectors" and allocates them to individuals/teams. This stops the whole section observing the same area and potentially missing things in front of them.
I don't see this being all that difficult to model. In fact, you could even use the existing "Fire at Location" command menu item, and then have the sub-menu offer "Slow rate" and "Rapid Rate" or "Watch and Shoot" (where for mortars it has "Single round, 2 rounds, 3 rounds" etc).