...it's tough to confirm if what the did was consistent.
You bet, Dave. Thanks for posting that nice array.
Warrin's tough. Here are some pinions from reels marked "Warrin/Maker":

And here are some from reels marked "Warrin's First Quality":

IMHO, Warrin may have used those pinned pinions until he decided that the more common, square-hole mounting was easier...or he switched suppliers. Also IMHO, your bottom left and my bottom right Warrins were made by Karr. I've never seen that "D-shaped" pinion hole on reels made by anyone else.
I suspect that we'll never be able to differentiate among the makers who used square pinion holes.