Hey I'm new to these forums, but I wanted to say that I really appreciate you transforming this mission into something I can enjoy without worrying about hackers and morons.
I do however want to echo some of the requests for more units at the beginning, because it is wholly unrealistic and quite depressing to have a base with a plethora of vehicles (which you can merely drool on because the tank crew has magically disappeared) and no additional soldiers or marines to aid you in the conquest of a 250 sq mile island.
You could really use some poetic license here and create a back-story that involves any number of different circumstances. For example, You're a part of a bloodied platoon/company that has retreated to their last bastion of defense. You, being the Sergeant fed up with retreating and following orders from an incompetent Captain decide to rally a Squad of men (out of maybe 32 running around the base) who randomly accept your offer. You then become the pillar of morale for your men and the rest of the base follows you, thus explaining the rank increase.
If anything, have the crews that can man the vehicles next to their respective death machines or floating around the base. It just irks me because MP Evolution has the prefix (COOP30) which implies that it is meant to be accomplished with a platoon of human soldiers from the start, and those 20-30 can also individually call in their own AI squads (so figure a Company sized force) towards the end of the mission. I feel as though I'm just playing the MP version of Evolution by myself with the ability to be extracted by an invincible Loach, and save my game.
I'm sure you were scripting one night and thinking the same thing but some food for thought at any rate.