I thought about another way to go at the Divine Realm that you maybe might find more interesting, silveroak. Let me propose an alternate mechanic for the Divine Realm.
Imagine that the Divine Realm is not the expression of God's divine nature, but rather the expression of the gods' divine natures.
What I mean is, let's imagine the Divine Realm comes from the divine nature of any god, not just the Christian one. The old gods of yonder had divine auras, not faerie ones. The Olympians, the Nordic deities, the Babylonian gods, the whole pantheon of old Egypt, they all produced divine auras, and their priests called upon divine powers.
Now as people drifted into Christianity during the last thousand years, they started to abandon the old gods they used to worship. Those gods still exist in the Divine Realm, and their power is still Divine. But their presence in the mundane world has slowly disappeared, replaced by the Christian God. As their presence in the mundane world has withdrawn, Faeries have stepped in, eager to take the vitality derived from playing out their roles, much like they've taken on other roles that were not originally Faerie to harvest vitality. The old, Divine gods still exist, in the Divine Realm, but what you usually encounter in the modern (13C) world is usually just Faerie impersonators.
Thus, cults that have survived the ages, keeping true to their original gods, would have Divine powers, and use the Divine Power row from the realm interaction table, effectively trumping Infernal, Magic and Faerie, as should be. Because they wield the power of the true gods. Other, more recent cults, have just been duped by Faeries, effectively worshippinh Faerie False Gods that are not, in fact, the actual gods they pretend to be. Much like the Infernal False Gods from canon.
The game world would be much like it is in canon, with Divine auras mostly being aligned to the three Abrahamic religions, but in some ancient workship places you might still find Divine auras related to the ancient gods, if their worship had somehow managed to survive the onslaught of Christianity.
The true old religions would become something similar to Ancient Magic, long-lost secrets that could somehow be unearthed from the sands of time or have survived in fringe areas (fringe only relative to the main setting, of course).
It would also explain why the same God could be on the side of Judaism, Christianity and Islam at the same time, helping each one against each other. They would in fact not be the same God, but three different ones, just all of them under the jurisdiction of the Divine Realm as they are all divine. Just like the Roman Gods, for example.
I think this could be a really fun setting premise, and it wouldn't change things much for most of the game.
Just an idea.