Considering that the aliens are an amalgamation of several races, their equipment doesn't all have to have the same aesthetics. PHALANX explicitly uses equipment from several sources, so I don't see why the aliens shouldn't. The alien tank should probably start with flight capability, whereas humans have to upgrade to it, assuming flight ability is still planned.
Incidentally, if scout UGVs are going to be added, would it be possible to make them troop carried equipment? Current tech quadricopters are entirely small enough to be carried in a backpack, and still be useful. Is it possible to spawn an actor during a mission?