Stupid question perhaps, but how come some people are on the leaderboards twice? That seems a little silly to me

Yeah i'm also confused on this. Like in 1000m speed skating the same player is duplicated in 3rd and 1st place...

It seems that you simply get more entries when you play on another console (Wii/wii U) or if you select a region (none selected and EU gives you two entries as wel). I haven't ran this game yet (planning to tho) so it's not like my opinion is incredibly important but as an "outsider" it looks very weird.