It may be worth changing up the categories here because it doesn't seem like there's separation in the right places.The D3 leaderboards themselves don't separate whether the run was MP or not. Just that it was completed and who was included in the group.Whenever Blizz decides to include the Sprinter/Speed Racer Conquest.
It may be better to just add a 'Players' column to that and list them as being part of the same time. That said, the MP boards can be taken out.
As for HC, it represents a much more entertaining run as either NG or NG+ for obvious perma-death reasons. The classes really don't make much difference in NG+ because there's always a way to get a speed bonus through gear like Warzechian Armguards, Krelm's Buff Belt, Wreath of Lightning, and Boon of the Hoarder as examples.