We think the old timers didn't have or use much, if any, knowledge of music theory. Probably true to a great extent, but they must have had a lot of intuitive knowledge of the subject. Otherwise, how did all those myriads of "strange" banjo tunings come to pass?
When I was a kid, I could tune my guitar between standard, open G ( aka Vestapol? ), and drop D. I could do that because those tunings were open tunings in the scale I grew up with ( Don't remember what that mode's called , Dorian? ). But the "weird" ones, like F#DGAD and double C, I didn't even know about, leave alone find the various chord fingerings.
So isn't there some kind of intuitive music theory knowledge at play in the development and use of those tunings?