Hi Ted. All the old banjoists say that there was a "North Carolina" style which often used three fingers. The earliest one that's on a film is Smith Hammett. Scruggs and Jenkins sure knew about him, and of course the most famous was Charlie Poole.The one undeniable fact is that no one played it with the fire of Scruggs. Don Reno came close, but he was more of a "chord" guy.
Wiley and Zeke Morris both said in recent interviews that Scruggs was fully formed when he was playin' with them...long before he joined Monroe.
Cheers
Rick