You have to remember how big Ellington was, and during the depression swing era, the size of crowds the dance venues could hold: anything from 2000-5000 people seven nights a week. He also had a marketing strategy from the late 20s onwards of serious music with dance interludes and that's why he was dressing like it was a classical performance.
Johnson by comparison, was playing in hick roadhouses and in a musical style, already considered old hat and out of date. The rest is myth.
I notice a similarly between the styles of Charlie Watts and Edward Sexton. Is Charlie one of his customers?