Surprised you didn't stick Josh White in there somewhere. I saw him work a couple of times, even after he had had operations to scrape the arthritis calcides off his hands, and he was pretty awesome. Never saw him flatpick, but he could do a lot of FPing runs out of his fingerpicking style. Also never heard him try flaminco, but his blues style was pretty close to jazz at its simplest.
Also someone I haven't seen mentioned, but who always struck me as a pretty extraordinary picker was Roy Clark before he prostituted himself for the big bucks on Hee -Haw.