Groom Marth

Not really... None of Green axes can better suited for Brave axe role as Frederick +atk...(And Cordélia)

I dont imagine better weapon for Marth than his... Its like 18mt, has good spd, workable outside CAV emblem...
You can make refine to make him tank or Speedy.

I liked him, has not the worst res amoung cavalaries, Also a good start for def...

He hits 45hp and 34def by weapon refine, Also 39spd If you want... He Is good even outside CAV team If you dont use Brave axe or he Will be another Titania at player phase.

Plot Twist - He has limited merges.

In all seriousness, though, I wouldn't say he "outclasses" the other Axe Cavaliers. He has less defense and attack than Frederick (who can actually be made into a speedy axe cavalier thanks to IVs).

He doesn't outclass them per se, but is certainly high up the rungs. He has the speed and balanced defenses/attack to be a good brawler, and can still do decently under desperation. He's more comparable to Spring Alfonse, but loses somewhat due to lower attack and the inability to increase his stats via boons.