the solution is simple:
make troops die when they take ANY kind of damage. Explosion, bullet hit, HE ammo round, they get run over, etc.
Make the map room require 50 troops to capture.
Make each troop-carrying unit in the game deploy 50 troops.
Thus we can have invasions of the lemming-people spewing or paratrooping out of goonies/LVT/M3's and we can shoot at them or bomb them to our pleasure.
Add squishy-screaming sounds to troops as they get smacked.