I suggest the nature of federations needs to change. I have two suggestions:
1. A realm can only be federated with one other realm.
2. Diplomatic relations for federated realms are all the same- if one federated realm wishes to go to war with someone, the other must as well.
I suggest that the federated realms be allowed to select which one realm they wish to keep as their federated partner and the rest be demoted to alliance.
