There are a lot of wild race formats in cycling track races.
Premes (primes?) are the most straightforward, you get cash for finishing a lap (they announce which lap at the start of the lap) in first place. The Africans would be all over it.
There are also points races, where finishing the total distance first doesn't necessarily matter -- all that matters is who finishes with the most points. Points are awarded every couple of laps for being at the front, maybe 5-3-2-1, but sure you could also award extra for being first to arrive at the finish, or you could change the amount of points or number of people getting points.
I think it would be fun to have a mile biathlon (they have something similar in cross country skiing):
-First, get everyone to do an individual mile time trial on their own.
-Then, do a mass start mile where everyone starts behind the winner.
-So for instance, maybe you have a time trial where Asbel Kiprop time trials a 3:49.XX, Silas Kiplagat runs 3:50.XX, and both Bernard Lagat and Mo Farah run 3:51.XX.
-Then in the mass start, Kiprop goes at the gun. A second later, another gun sounds and Kiplagat goes off. A second later, Lagat and Farah take off after them in pursuit.
-Does Kiprop just start hammering from the gun? Does he jog and try to sprint the finish? Would he even try very hard during the time trial and hope to save it for his kick during the final instead?
More combined events. Have them run a 400, a mile, and a 5k, and multiply the gaps in the 400 by 12x when you add up the total time.