User blog comment:PacmanIsGr8DontH8M8/Smash 5 Change Polls/@comment-24357950-20150408183219/@comment-8182065-20150409235834

Well, Lucina was originally supposed to be on Marth's character slot (like how the Koopalings or Olimar and Alph are); however, all the clones aren't "perfect" copies of their original characters.

-Lucina and Marth have different hit boxes (her height and sword affect this).

-Dr. Mario has a different down special, as well as using medicine in battle rather than fire.

-Dark Pit and Pit are virtually the same, but final smashes are much different.