An interesting question but i s'pose it all depends now doesnt it? If the Romans, as well as having Air Cav, also have the other equipment on Air Cavalry choppers such as miniguns and missles, well than it would have been one helluva one-sided battle.

With just the plain old Air Cavalry chopper the Goths wouldnt stand much chance unless they boarded the choppers when the Romans tried to transport troops around the battlefield. That is assuming of course the Romans only had the choppers!