First, thanks for posting the other images of Vollard. I tried to post that to you earlier today, but there was a glitch and I had to run before solving it.
That is one of the best Catlin images I've ever seen. It is perhaps freer because it is unfinished.
He was weak on landscapes and figure groups . . . but when he was concentrated on a single portrait he was amazing. Here's another one I really like:
See-non-ty-a, an Iowa medicine man.
I can't find a good copy of the full-length portrait of Old Bear the Mandan medicine man with all his considerable regalia, but in the original it is stunning.