I use the faction leader on the front lines if he's a command type. I don't have a problem with this from the early Roman historical perspective. For example, when Scipio Africanus's father was killed in battle, the Cornelii did not collapse or devolve into civil war. Rather, a new member of the family took up the mantle of leadership and led the family on to even greater glory. The faction leader's welfare should be a factor for other factions, however, such as the factions whose leaders historically were kings or warlords (Gauls, Greeks, Seleucids, Ptolemies, Macedonians, etc.).

From a gameplaying perspective, I do miss the M:TW tendency of the occasional civil war and/or factions randomly reappearing (except for the unspeakably annoying Papacy). It added a level of difficulty that I found enjoyable.