MAN FIGHT.
While it might take longer, having normal dudes duke it out with one or two super heavies around has two effects:
1) Makes those super heavies that much more epic (as they should be).
2) Makes heroes out of normal dudes who get the last hit to rip the titan / flyer to the ground. Case and point being that dude who punched a titan to death with a powerfist.
All that being said, I won't be bringing any superheavies. I'll probably bring my exact list from the megabattle.