Guys. What Sirion, Eppy and Nivemus did should not be illegal. Coordinating a sneak attack to stop a takeover they all didn't want to happen should not be a wrong way to play the game. It was good intrigue.
Just as they did, you are completely ignoring the alliance bloc restrictions.
Neither Sirion nor Nivemus is allied to Eponllyn, or has any other particular reason to aid them in their war against Shadowdale.
If we allowed this sort of thing, they would be nothing more than tissue paper.
Sirion, Nivemus, Eponllyn, Caligus, and Yssrgard need to figure out who their actual allies are, and who is just a friend who they enjoy hanging out with, but
do not aid in military matters. Because together, they are an alliance bloc that controls over half the human-owned regions of the continent. "But they should be allowed to—" no, because that's blatant circumvention of the rules.
Is it new? Yes.
Does it take time to develop new cultural background, especially in a place like the EC? Yes.
Does that mean it's OK for them to be allies-in-all-but-name now, six months from now, a year from now? No, no, and no.
This is exactly the same issue that was being dealt with recently on Dwilight, and they were (with one notable exception) able to deal with it in a mature manner.