Thats one of the big things about this game as far as balance. nod/Nod/NOD/BoN doesn't require AS MUCH teamwork on many maps with their stealth units that are designed for standalone roles, or the flame tank which can individually distract an entire base for a minute.GDI however, requires more teamwork, especially on the base defense maps, because the Obelisk can destroy most any one person by itself, without actual people supporting it. GDI requires massive suppressive force most of the time because stealthliness comes by a lot harder.
Also, GDI's strength is vehicles, which are bigger and require more coordination, where as their adversary's strength is infantry, which can hold out against multiple units on their own, or in the SBH's case, play with guerilla tactics.