Well yes, it could be anyone of those, but neither of these guys rhymed, there's a lot of evidence about them and non quotes them in rhyming pattern, the only ever rhyming mage/wizard was/is Bellegar still. And why wouldn't he have a cat familiar? Even Zandalor had one (well Arhu wasn't really his familiar and not even a real cat, but still you could say that they both acted at least that way). Bellegar's good heart fits into the story of the cat, leaving it in the library to protect it. There were only Magisters there and they were thought to be good overall, you know the Divine Order and stuff. All that with Dallis and her experiments was kept secret.