Yeah I remember that, though I figured that's a case of story and gameplay segregation. Can't exactly have her copy Chrom's motions because that would be boring, and Marth copying hers was out of convenience. He and Lucina have different fighting animations in Fates iirc.
Many animations in Awakening were shared between various classes though.
I wasn't talking about Einherjar Marth, Lucina's own original Awakening battle animations were mostly homages to Marth's
in previous games. That stance pictured above, the way she holds her sword in front of her face in some animations too (something that's mostly missing from both Marth and Lucina in Smash), her backflip, both her piercing and slash animations for skill activation...
Marth has some new animations in Fates, like his "waiting" stance, before getting in an actual battle stance, which is different now, but they're still rather similar. Lucina and Marth still share that same "counter" stance for example, and both still hold the sword in front of their head as part of their attack animations (although the animation itself is different now, since it flows from their pre-battle stance animation, which is different now).
Marth now has a multi-hit looking attack based on his old Rapier animations... but Lucina also got a similar looking attack, with the main difference being that Marth's attack seems to be faster and purposefully old school, with what looks like skipped frames (kind of like Wario in Brawl) while Lucina's has a fluid animation.