Human teams are limited to three people. So why doesn’t it matter how many instances they used?

This is what the argument is? 10 years ago if you said you could do this with every computer on the planet and every computer scientist focused on trying to create the code to do this I would’ve given you absurd odds against it getting 12 problems right on ICPC. 10 years ago it couldn’t even reliably parse the question statement.

Human brains and cloud instances are not remotely equivalent. What you can compare on an equivalent basis is cost.

Or energy usage.

Cost is inclusive of energy and a lot more. It's a better metric.

All instances of any given model are kinda the same, for lack of a better word, "person": same knowledge, same skills, same failings.

I bet with human teams it'll take longer to solve a problem the more people you have on the team.