I think there's a workaround - Lets say there are two armies, your player army and an allied army like the prologue's Captain Decius. You only have like two weak cavalry units and Decius has some badly shaken infantry but the barbarians have a truckload of baddies. If the 'barbarian' army kills all of captain Decius then he is triggered to automatically rout (ie. leave the field in 'victory') and if you survive till then, then you win the game.

Sounds possible, I hope it IS.

Thanks very much,
Clare (Harlechman)