My main issue with Fire Emblem is that 4 out of 8 characters use the same moveset with very minor changes at best. And while I understand why, I'm still not happy about it. Chrom absolutely was not necessary, imo.
If we had to get a Three Houses character, Claude would have been the ideal candidate.
He would've been a PoC (not just alt) in a game where there's none outside of a few costumes.
He would've been given a bow as main weapon - which also was the reason I'd been stanning for Decidueye before Ultimate's release. There are no dedicated bow users in Smash to this date - the Links only use it in one move, and Pit's bow function also is only used in one move. A character like Hawkeye in MvC3 would have been really cool.
Edelgard would've been a good second choice - she's popular, would add female representation, but I also feel like the difference between an axe user and a heavy sword user, i.e. Ike, is overstated. In the end, she likely would've felt very similar to Ike.
Anyway, Fire Emblem has been a big success recently, with Awakening and Three Houses having performed excellently, and yes, it has a rotating cast. However, while it certainly is on upward swing, I can't say I agree with the notion that it 'deserves' as many characters as Pokemon or Mario (and frankly, I don't count Daisy as an actual character, she's literally just a glorified alt costume since the single difference she had to Peach was patched out because it was accidental).
Personally, I've always wanted the more recurring characters such as Anna, and deuteragonist characters like Micaiah over the boring swordlords. The only addition that I don't mind at all is, ironically enough, Corrin, because they actually play incredibly differently from the others, and barely even use their sword in their moveset, rather transforming it into a spear or partially transforming into a dragon instead. In a vacuum I would be fine with Robin as well, even though I would have preferred if their entire moveset was made up of magic rather than having the sword for the brunt of their moves.