I personally don't hate swordies or FE characters in general, it's the Marth clones that I personally have a problem with. Ike, Robin, Corrin, and Marth himself are great FE reps with unique movesets and attributes, that's all good and well. And a clone or two don't hurt, most of the other franchises with big character pools in Smash (Mario, Pokemon, even Zelda to a lesser extent) have a clone of the most prominent character from that series. So what else do we got?
Roy? Inverts Marth's tipper mechanic, has fire attacks on his sword, and despite sharing specials, they and his other normal moves have slightly/completely different animations and functions, putting him on the border of echo and semi-clone territory, solid character. Good example of taking a preexisting character and building off of it to make something unique, almost like Luigi... what? Another clone character? Um... okay, let's hear it, then.
Lucina, neutralizes Marth's tipper mechanic for more consistency, and... shares the same specials, attack animations, etc. I won't undersell that changing the tipper mechanic does change the function of these moves to a degree, but there isn't the same amount of flair or uniqueness that Roy had. While things like Counter and Dancing Blade are almost one-for-one the same among the three, compare, say, Marth's Jab to Roy's and Lucina's. Marth's is two swings of his sword, covering a circular area in front and slightly above him. Roy swings his blade with a revers grip in a single movement, covering an area right in front of him. Lucina's is... almost a carbon copy of Marth's. You get where I'm going here?
And then we get to Chrom, who does it a little better, and a little worse?? Let me try to explain myself. He's an echo fighter of Roy, which is kinda weird when you think of it, an echo fighter of a clone character. Anywho, Chrom is an echo of Roy, and is to Roy as Lucina is to Marth, neutralizing his reverse-tipper. And like Lucina, he shares the problem of basically copy-pasting most, if not all of Roy's attacking animations, just removing the fire for some kind of wind/bluster effect with no variation or new animation. And on top of that, instead of Roy's up special modified, he has Ike's up special, for some reason? I mean, bonus points for having one move to distinguish himself from his originator, but then that drags Ike into this echo mess as well.
My point is, having a lot of FE characters/anime swordsman on the roster is fine with me, like how we have a lot of Mario or Pokemon characters. What's not fine to me is 4/7 of our representatives sharing almost the exact same framework. If we're going to have these many echos of Marth, I'd rather they at least do something more to distinguish their self from Marth like Roy does, with slightly different normals/aerials to make him actually feel somewhat unique. Either that, or I'd rather we cut out some of the fat, or at the very least, put one of the other unique FE characters into the copy machine, I'm sure Marth would be happy to not be the one stuck under it almost every game since his debut.
Reading the OP again I realize only now this isn't exactly what was being brought up, but uh... close enough? Sorry about that. Hope someone can find some value in the points brought up here.