with the TOTAL WAR engine you don't really have the possibility to represent those little skirmishes against neighbours as the scale of the game is far too big for that thus you never actually have a local raiding party at your command but only those large alliance armies or huge masses of emigrants, looking for a better place to live. after all the idea of Total war does not at all fit for most of the factions featured in RTW(and EB) actually rome is the only one that I can think of, imagine carthage fighting a total war, ^^ same is for the "barbarian" civs.

on M/M it should be possible with a phalanx wielding faction otherwise you need to do pull through the initial phase fighting yourself or auto_win ing as AI generals do get boni, considering how difficult it is to get high command fms the ai has quite a lot of them ;)
-the phalanx thing is because it seems that phalanxes are favored in auto resolve, on the other hand it's not a good Idea to auto resolve with a HA army as they usually preform much worse than in real battle.