It would seem the natural flow of the game would cater to having individualized battle styles at each point in the progression of base caps. Since taking capture points is the endgame, for the most part, there would be a sequence of more heavy vehicle >>> vehicle/infantry >>> infantry type fighting.
That is what makes Planetside so great though. Having a front line of ground armor and air units to clear the way for the troop carrying vehicles and making sure the troops get inside the base, initiate the hack and stay covered from reinforcements. The ability for each player to play the game as they please (ie. a tank operator, pilot, ground pounder) only reinforces that concept as you don't have players pulling multi-role tactics trying to cover more ground.
I am getting giddy just thinking about it