well the best way to know is always to try it out on costom battle... still, as it have been said already, Moral will often decide wich is the best... even if you're outnumber 4 or 5 to one. For example, Germanic units have in general very high moral, comparatively to gaul or even cassee (when not using champion) a unit of germanic swordman can easily hold their own against multipkle ennemy, provided that your general don't die. and thus giving you time to rout the numericaly superior ennemy. I'm speaking about germanic situation because I gues that there are similitude between Saba and Sweboz in the fact that the two faction are often outnumbered in battle...