I don't really see what people otherwise expect, based on previous Strat history. Trust means everything.
We
could - or at least have had a fair chance - defeated them all in Strat 3, through the (first) mighty HOLY LANDS DESERT CAMPAIGN, we were holding their "proxies" off quite well until wolves/fenris butchered the alliance (via purely meta-gaming) in favor of UIF support; Otherwise we'd probably have a major alliance today, powerful and strategic competent enough to fight any major group.
Betrayal, neglect, being untrustworthy, not coming through on arrangements etc, are what creates these super tight alliances, because people will continue to try something new until they find someone trustworthy, someone dependable, someone as dedicated as themselves, and when that happens it'll stick forever.
The only side I never experienced any betrayal in, where people came through on promises and didn't bail "just because" was with GO/DRZ (UIF), every other alliance or group back-stabbed each other or didn't come through on some sort of deal (troops/items/gold), leaving one side completely skewed in a war, and if you've spent a good deal of time arranging something for it to fall flat to the ground due to others not doing what they told you they would, well that just sucks, who would want to go through that multiple times? Nah you stick with those you can trust then.
All needed is an Alliance where people will actually do for each other what they promise, for just one full campaign to the end, which takes time and effort, then you would have more than a fair shot against the strongest factions.
Though unfortunately I think no matter what someone will betray that alliance
(which sorta lends to the realistic medieval feel too I guess
)
