alt Hacker NewsI know people who will adamantly insist that keeping classes within similar development ranges is harmful and will vociferously reject any such proposal, up to and including things such as "gifted" schools and the like.
It's why some schools in (iirc) California did away with higher maths like calculus entirely.
Sadly, it seems there's nothing actually common about common wisdom.
I will admit that I never heard a serious argument from anyone that did not rely on issues not related to individual student's education. If you have any materials on those, I would love to read some of it.