What I will add to O'Tink's answer is something you and I already discussed on Blurt (or maybe A-Mug?)...because I felt much like John Ford in that for a long time, I always thought The Duke was a really POOR actor...all swagger and drawling about pilgrims...and then I saw THE SHOOTIST, and changed my mind fast! (Which I learned later was his last film.)
Anyway that made me curious about what else John Wayne did...plus you showed me a few of his greatest works...anyway, here is the quote I love from John Ford:
'the critic Joseph McBride says John Ford, who had directed Wayne many times, saw “Red River” and told (Howard) Hawks, “I never knew the big son of a b*tch could act.” '