I agree.
Some of them do arrive in trucks already, up to 25%.
Unfortunately with the tolerance of One-Man-Army roleplay(?) and no balancing effect for loading one-self like a packmule (120kg loadouts are the norm) on SGs server, the result is 80% of players carry around AT launcher + carryall with 3+ rockets ... So as you say, it is not appropriate to have the majority of enemy deploy on transport trucks.
In other news, CSAT has won 6 of the last 10 counterattacks. After some play this weekend we'll see where its at and decide to dial up a notch, keep as is, or dial down a notch.