There could be a 9-round tournament for 512 human teams, vs the current 4096 12-round tournament for around 600-ish human teams and 3500 or so bots. You could include a preliminary round so that all human teams could play, otherwise you could end up with up to 1/2 the human teams being left out, or having to include a lot of bots.
After 3 rounds we are now down to 512 teams, so an all human tournament would be equivalent in length to what remains of the current tournament. But a majority of remaining teams are bots (estimate 62% based on first two pages of matchups). This is about what you would expect based on a random draw, where some bots play other bots, and perhaps 15% of bots pull off an upset against a human opponent. Given that some of the humans are little more active than a bot, or were concentrating on training or avoid starters going 100+ minutes, or were on the road, 15% doesn't seem too unreasonable.
I expect that a few bots will advance another 3 rounds (to the final 64), but should be gone after that.