Maybe some kind of Alliance fatigue where if they actually win some territory they will push that fatigue limit up until they break the alliance off. Alliances should be defensive only so any kind of offensive victories should chip away at the alliance.Yes, game needs alliances. This was obvious and most of us come to this conclusion at diplomacy developments thread.
I offered alliances idea to armagan too. It is “partly accepted” but we will talk about details at October. I offered when there is an alliance 2+ allied factions should be able to make a siege to a fortification together or they should join battles on map when allied kingdom party is attacked or they can defend allied settlements or they can get more open slots at settlements of allied kingdom + we should find negative side effect(s).
This feature will probably increase battle variety on game which will result in better gameplay experience and it will be slow down snowballing (if nobody make alliance with most powerful factions) which again results in better and more balanced gameplay experience.
Imo biggest problem of alliances feature will be “what will be its negative effect?” What will stop factions making alliances all the time? There should be a cost or some other negative effect. Otherwise making alliances will be always logical. One possible solution is there can be a cost which both allied factions pay and it can be more expensive when factions are stronger. There can be more side effects.
Logic behind this being alliances are great until they have to choose who gets the reward, thats when the contention begins and the alliance begins to break. Settlements can't be split, so one side will be upset they didn't get it.