Rather frustrating that there is so little thought to enjoyable gameplay here. If you simply made it so that downed personnel did not disappear after an assault you would add a whole layer of both tactics and enjoyability. It would incentivize placing a layer of ,essentially fodder, personnel at the front line to slow down enemy progress while giving the player something to enjoy given what, essentially, a pretty dull experience. I might also toy around with removing the players ability to shoot and adding the ability to order the personnel to move to a new position to add more strategy and emotional impact to the game.
Wish I knew how to mod this thing.