So, something like Natural Selection?
I'd like to see something more of a compromise, though. The MCV driver deploys, then controls the base, becoming the commander. Basic infantry are controlled by the commander. Tanks are deployed without drivers, and guys have to be sent into them. Commandos, however, have much better stats than basic infantry. This extends to them taking over vehicles. They are also player controlled. Commanders can give them general orders which they are rewarded for following, perhaps with increased veterancy points, but they can disregard them.
I don't know what you mean by Natural Selection
I think it would be a complicated mode to code on (the devs need to know how to actually code a proper RTS, and various buildings and models need to be made) but at the same time, sounds awesome. I don't suppose there'll be too many complication with buildings, seeing they're most likely either one big mesh, or prefab
Random Scenario :
Commando : "Sir, I need a Mammy ASAP!"
GDI Commander : "Noooo, I'm saving our precious money for APC rush, go F yourself!"