I've been writing about squad-level actions in ArmA2 with an special emphasis in command. What I have done before is to split my squad into fireteams by assigning different Marines to teams red, blue and yellow. Sometimes I would even put the three SAWs into one team. Though this type of arrangement gives you an exquisite amount of control, it can become a handful when the bullets start flying.
ArmA2 has this new "High Command - Commander" and "High Command - Subordinate" game logic that allows you to create any command structure you may want. The versatility of ArmA2 is really amazing.
Using this "High Command" thing allows you to command each subordinate fire team more easily (not that much keyboard wrestling) either from the first person or map view.