I forgot to add this when I was talking about the FE13 re-designs. One thing to keep in mind was that Marth and Roy were among the first three lords to become DLC. Marth was DLC at the game's release, and Roy's was DLC a week after the game's release.
Ike's DLC was released months after the release of FE13. Moreover, his re-design was met with a strong negative reaction by not only Western Smash Bros. fans but Japanese ones as well.
From what I have seen on Japanese image boards, the most artwork I have seen of the re-designed lords are Marth, Roy, and Micaiah. With Micaiah, I speculate the the fascination with her re-design is due to scantily clad nature of it. I think Roy's re-design definitely would help distinguish himself from Marth and Ike/Krom.
Marth's FE13 re-design makes him look lighter and thinner than he does in any other incarnation of his, which would be good to help establish his place as the light, quick, and weaker Fire Emblem character. Ike om his FE10 incarnation (or Krom) with their exposed muscular arms and being older shows a sword-wielder that has an emphasis on strength (with a slower speed as a means of balance). Roy not looking to be particularly muscular like Ike or thin like Marth, would be medium between the two.