IT seems to me like many of the gangs abuse bad AI by having one player hit a guard and running off the map and coming back on it, a simple improvement would be making any faction that attacks the enemy as hostile so if they see any members of that faction they will attack them on sight.
Half solutions? Its called changing something, seeing if it stops people from abusing bad AI and if it doesn't see what other improvements can be made, this is often easier to do than to suddenly come up with a solution that will fix everything at once. Tbh the only people i find that would dislike a "half solution" like this are those that abuse the ai have their gang sit in the town while 1-2 of them pick off the militia and guard their gear if they die, at least this way its an all or nothing battle with an actual chance to lose your gear instead of only having to worry if another gang is online. I've seen 15 militia die to a single player abusing this, it shouldn't happen.