This sounds plausible. But otherwise, there are "tournaments" like the TCEC which is for bots only and the way it works is, the bots are adjusted to play a spec

This sounds plausible. But otherwise, there are "tournaments" like the TCEC which is for bots only and the way it works is, the bots are adjusted to play a specific opening and they're on their own after the Nth move. Stockfish has been dominant for a long time. And a later version of Stockfish would outperform an earlier version given the same time control.