All 3 of them are pushing each other to go faster than they ever could training alone. It makes sense to me.

I'm not a big Olympics guy but I watched the long track and field race during the Paris games. The 3 medalists were on paper slower than like 4 or so guys that dropped out of the lead at the last lap. The lead guys were running faster than they ever did and then gassed out. Then the second guy fell and so on. The gold medalist never ran that fast in his life, but was able to because of competition. It happens.