So if live 1/2 skill level is compared to 2nl online how come some people claim 10bb/h winrates which then translate to ~40bb/100.

Could they be overestimating their good runs, but to me this seems odd since many people make claims of such winrates.
Other factors could be live reads and relatively lower rake compared to micros online.

What do you think is 5bb/h more realistic, which - mind you - is still ~20bb/100?

p.s. I'm from europe where population is not as OMC-ish