It has nothing to do with the Circle being the better system and a lot more to do with the fact they can't handle the inevitable abomination that will eventually come. They don't have access to public funds, a semi-continent spanning organization, and a ton of lyrium. They can't handle it. The rest of Thedas can. It's about time everyone acknowledged magic is dangerous and there needs to be someone to deal with it if mages will continue to be born, and mages always will continue to be born.
They have access to the ironbark cure. And not having fear and oppression about magic concentrated in those demon beacons called Circle towers should lead to far fewer abominations anyway. I'm not saying that it does, because we don't know, but that's my view on it.
The best person to handle a powerful bad mage is a powerful good mage.
There's already a Morrigan'nan in the legend of Luthias the Dwarfson which took place in -350 Ancient while, if we accept the story Morrigan tells us as veridic, Flemeth was human around the Towers Age (as in 600 years after Morrigan'nan died).
We don't even know if Morrigan is Flemeth's biological daugther.
Even if she is and the name has some importance to it rather than it just being a somewhat common Fereldan name, Morrigan has older sisters like Yavana who didn't receive it and whose eyes are just as golden.
What is the timeline for Tyrdda, anyway?
Yeah, I didn't mean it was actually Morrigan, more like a type or an ancestor.
Not sure on Tyrdda. There's not much on the wiki about it yet.