Well the problem with the likes of Huns is that in numbers with cantabrian circle, horse archers are just too good - and horse archers are basically the Hun army. Bear in mind that without the horse archer restrictions, the Huns are probably the most powerful faction in the game since all their cavalry units are that little bit larger than usual, so taking about 5-6 cavalry units, you basically get a free unit in terms of numbers. Their infantry is not so great for a reason, but their infantry is still effective (Shiltroms are great holding units), but you just are not going to win a game with it alone.

I am though thinking that the Huns can be an effective force with cantabrian circle being banned and a general limit on the number of archer units mounted or unmounted, basically so as to try and make the game "fair". You don't actually need cantabrian circle if you are prepared to keep your horse archers moving in different directions, but you obviously cannot do this with your entire army. The extra cavalry numbers the Huns bring to bear do I think compensate for the lack of any killing infantry.