I've played on the 5k servers, sure, you can kill a mammoth, but not if there's 4, and a dozen hotwires running around chaotically repairing them, not to mention they can have a med/mamm sit and hold fire on the tunnels and prevent any1 from coming out that way either.

Kill a few mammoths, and on the 5k servers, more come, and all-in-all, it's in GDI's favor, flame tanks? good if there's only 1 mammoth...same goes for stealth tanks, it's nice if you can single out a target, but not if it's a small armada of bulky really tough tanks with lotsa firepower.