Tell me about it desh, the "scrub" courses, aka, Luigis Mansion, Peach Beach etc etc, are horrible in 12 players, either lead and get away from all the chaos with psycho luck, or, lead all race and go from 1st to 12th on the last corner.
Courses like Rainbow Road, Bowsers Castle, stop this a bit, though not always a guarantee.
1v1 will be more interesting, you either play for an item, or, you race ahead and drop what you can defensively, hoping to hit player 2 and get a decent enough lead in doing so.