A couple of militia spawning after choosing the "I've brought a couple of guys with me(...)" line from the mayor and the actual countdown starting after these guys are dead might prevent 3-4x bluesuit pack running straight into town berserk-mode capping a city, talking bout the current TC.
Anyways, back to the new scheme, I like it very much, though being a Halo player, I'd love to see things such as "hill contested", so that another gang could hop in straight into the last two minutes and grab a capture over a town. More importantly, random placement of the hill so battles wouldn't be so monotonous, giving some advantages for certain classes in some spots, making others useful in a completely different hill.