I'd like somewhat tweaked victory conditions for some factions. For example in EB I, those for Saba were more Islamic than actually related to ancient Sabaean politics. Perhaps there could be more subtle goals in some places instead of "conquer the following provinces" or "squash factions x, y, and z".
Hopefully the recruitment of sedentary auxiliaries for nomadic factions will also be facilitated. In EB I you have to rely on exploits to properly play the Sauromatae.