I would add Joe Cocker. Totally influenced by Ray Charles.
I agree about gratuitous arpeggios. I guess it comes from playing piano alone in cocktail bars at hotels. I prefer Benmont Tench style - playing for the song rather than overplaying. Oscar Petersen was great too.
Pee Wee Ellis once said (and I am sure he is not the first by far), "in music it is often more important what you dont play! It can be frightening to leave space.
This is very true in drumming - judicious placement of space is really important. The rhythm or groove is as much about the space as it is about what is played. Space creates feel. Space can also be thought of as dynamics - softer notes create space and contrast - great grooves have different layers of dynamics.
I think you could start a thread about leaving notes out and musicians that excel at it. Like great art - the blank spaces on the canvas are actually part of the overall composition - but amateurs dont understand that and try to fill it all in.