Yes, like your lawyer example there's plenty of evidence where outcomes for people doing basically the same work varies a lot across times and places.

Maximally small government / libertarian people would like to pretend that everything is about individual character because this would justify their preferred public policies, but thinking about it even a little bit it should be obvious that internal and external factors both matter.

I remember in a previous discussion here Walter was objecting even to the use of standard economic terminology around things like what wealth-creation means (dating back to Adam Smith's The Wealth of Nations in 1776), so I'd take his views here with a grain of salt.