Costumes (Will reopen later- NO NEW COSTUME IDEAS FOR NOW)

[Neslug]

I'm just wondering what cases can be considered a character change and what can't. Dry Bowser, again, appeared as a separate character in Mario Kart Wii but would he be considered the same as Bowser in this game (I realize he's on the list on the first page)? And Shadow Mario I talked about in my previous post is a different character in Mario canon (Bowser Jr.), but he shares the same physique with Mario and his design is effectively just a recolour of the plumber. So would Shadow Mario be allowed as a Mario alternate costume?

Sorry if this is a stupid question.