That's kind of a big thing to ask from Mario Kart though. I'm pretty sure MKWii stacks the decks against whoever's in top positions anyway.
On the Wii courses the deck is stacked against you, on the retro courses being in first is a massive advantage...in N64 Mario, in N64 Sherbert, in SNES Course 3, in DS Yoshi Falls, and most of the others too being in first is a lot better than being far back. The worst place to be on a skilled course is the middle of the pack where you are still being hit and everyone is tearing each other down, one or two players will break away and one of them is going to win it all short of 5 total blue shells (and 1 is honestly average). On those courses blue shells will decide the difference between 1st and 2nd or 1st and 3rd sometimes, never worse. The only courses that are not completely skill based on wii retro are Waluigi Stadium, GCN Mario (the two worst retro by far), and kind of N64 DK and DS Peach Gardens (the courses are extremely linear so everyone can stay close enough for items to determine most everything).
On the other hand on courses like Coconut Mall and Mushroom Gorge and Toad Factory and Moo Moo Meadows you do not control your own fate enough and luck is going to decide the difference between 1st and 5th place or worse. That people like these courses the most is stupefying, in general only really really really really terrible players. Rainbow Road, Moonview Highway, and DK Summit are the only Wii courses where skill matters. On Daisy luck determines 1-3, on Koopa luck always determines 1-2, and Grumble would be very skill based but it can be won by the first person to get a mushroom thanks to a glitch. Luigi Circuit always ends up too tight so blue shells ruin that course too much.
Honestly basically the entire difference to a skill based versus luck based course comes down to if a course has a bunch of ridiculously wide areas or if a course has a tight, well defined course. Think Wii Bowser (all wide sweeping areas) v GBA Bowser (has one wide sweeping area between a bunch of ridiculously narrow areas) or N64 Bowser (with the extremely narrow bridge portions).
Incredibly, the battle mode manages to have the worst courses on the Wii side too. Block Plaza is a terrible fucking piece of shit, really the worst course in the game, utterly luck based. Funky and Chain Chomp Wheel are almost as bad. Thwomp is amazing and Delfino Pier is pretty great but you still do not totally control your own destiny on either. Every retro course but Twilight House is perfect though, and Twilight is not as bad as Block Plaza at least, not even Mushroom Gorge is as bad as that.