So I'm only between Chapter 6-7 on the Golden Deer route, and I am really really enjoying Three Houses.
I've never really taken much issue with Fire Emblem bringing in Avatars, and while I have Mixed-Feelings about silent protagonists in general, it hasn't really bothered me yet.
So in RPGs I pretty much always play a magic class, or at least some sort of Hybrid. It was the thing I loved most about Robin, how Magic based they were by default,. Corrin had to an extent as well, though I'd say they tended to push towards the Physical.
Despite the versatility of the Class system and our students in FETH, making Byleth proficient in Magic is a giant pain. Yes they do have a bit of a bonus in faith, and a more Supportive Byleth is probably in the cards for a future play-through. But Reason, trying to focus on that as a supplement to the Sword of the Creator is well not great.