Olin was a lot of things, but a designer he was not.
The 21 was designed by a staff of people.
Browning designed the '93, which morphed to the '97.
The 12 was a group effort at Winchester, the group nominally headed by Johnson. It uses the takedown feature of the '97, a Winchester addition to Browning's design.
There's nothing new or novel about the 101 or 23, just existing techniques adapted to high volume production guns. The real heros of those designs are the process engineers who made it possible to manufacture good quality at affordable prices. The starting point of course was Japanese labor cost.
