Seig, I specifically mentioned land hierarchy, even if it isn't kings, and land hierarchies would naturally tend to develop, even without mechanical interference.
By remaining neutral when your land is part of a war, you could (not would) well be seen to be traitors to the land - you would be using the weight of your members to influence your land's politics in favour of Necrovion, rather than itself. I say in favour of them, because it may not be able to act without assistance from yourselves, which according to this statement, you would not give.
Long-term agreements rarely work on good faith, each side believes different things about the pact that the other half wouldn't agree to if known. The good faith view of the pact is different for both parties.
Interesting and unpredicted things are all good fun, but then I ask what the point of making the pact is at all, if it's all based on good faith, and you want such things to happen. In my opinion, if you write terms, you write them properly, or you just don't do it.