Okay, let me try a different tack. I'm wanting to approach this from a character-motivation angle rather than a what-do-the-numbers-say one, because I'm a writer and that's how I roll.
This covenant has been around for, what, going on fifty years (if I remember right)? Probably most of the inhabitants of the covenant and the farmlands that surround and support it were born and raised here, and have known Jaime Lannister (and most, if not all, of the other magi that used to live here) all their lives. The Muslims are probably rather fond of him because of his actions to protect them, their culture and their religion against the Reconquista. The Christians probably feel something similar, because the covenant has been in Al-Andalus for most of the time they've been there, and they have been treated fairly well (or, at least, not poorly) during their lives. Ditto the Jews.
Then, in the last year or two, everything just want kablooie. All but one of their magi was killed or lost at the Battle of Las Navas de Tolosa...not a single one of the men who went off to war last summer came back alive. (Which still boggles my mind...by comparison: during the Battle of Gettysburg, the bloodiest battle in American history, the 26th North Carolina Regiment started the first day with 839 men, the largest regiment on either side; three days later, they were down to 152. An 82% casualty rate, with “casualty” being killed, wounded, taken prisoner, or missing – the highest single-battle casualty rate of any regiment during the entire war). um...sorry...history geek-gasm. Where was I?
Oh, right. Um...so. All of their magi are dead and gone. All of their able-bodied men are dead. Like a lot of people, if not most people, do in times of great tragedy, they turn to their faith and to each other (i.e. Divided Loyalty). Yes, they are Cijarans and will stand together against whatever enemy may come their way (literally or figuratively)...but for the first time in a long time, they are not just Cijarans, but they are Cijaran Jews, or Cijaran Christians, or Cijaran Muslims.
Then, to add insult to injury, Jaime Lannister, their lord and master, their protector and benefactor, invites a bunch of...outsiders to the covenant. (I have a feeling that few, if any, of the residents know of his plan to leave). Why are they here? What are their intentions? Only Cygna and maybe Serrano have Gentle Gift, so all of the other newcomers will have to overcome the social effects of The Gift with regards to the residents in addition to what they would normally have to deal with as newcomers to a Strong Community.
It should be easy to see, then, why the residents are going to have a hard time trusting the newcomers, even the ones with Gentle Gift (although they may have an easier time getting the residents to not mistrust them so much than the others). The residents don't really want the newcomers around, they have no idea how they're going to be treated under the new “regime” (and in fact, from rumours they may have heard from other parts of the land, may expect to be mistreated by these apparently Christian interlopers).
Sorry...past my bedtime, I'm rambling a little bit. But my take on it is that it feels to me like we're over-obsessing on the numbers and losing sight of the role-playing slash character motivation aspect of everything.
And with that...I've presented my take on how we should approach the Covenant's Base Loyalty, others have given theirs. As far as I'm concerned, it's up to Amul to decide how he wants to handle it, and I don't really feel like bickering over it anymore. So this is (probably) my last post on Covenant Loyalty numbers-crunching until we have a decision. I'm still working on the Population and Finances aspect of the covenant design, but the Loyalty debate is making my head numb.