I used to play a game called age of legends (which is dead now) and one of the best parts when it was in its prime was the community. Interaction with other players and clans (equivalent to our alliances) was very easy and kept the game going long after the devs abandoned it. I feel that more interaction would make this game go from great to fantastic.
Factions would basically be allied alliances. They can be made when one or more alliances agree to form one. Each would pay x amount of gold to keep the faction running and possibly gems to form it in the first place, to avoid abuse. Players can move between alliances within the same faction with a much shorter cooldown in war. There could be faction boosts too. Factions can be in a state of neutrality, conflict, or war. As relations go south, it costs less food to attack members of the opposing faction and there could be other dynamics too. Alliances would chat through a window accessible from the alliance menu on the right. Faction level will be based on the sum of the of the tiles that all members hold. More land = bigger faction. This would also discourage throwing wars.
Hope y’all like the idea and happy revolting!