Whether you like his nervous work or not, he was brilliant at attaining effect, so relative to himself, the whole brash gritty feel was appropriate. His revealing of the "underlying soul" of sitters was a calculated artifice - he just wore them out under hot lights until they grimaced. He did that to Marilyn Monroe, to the Royal Couple, to many others. And a number of images in American West were staged contrivances. The beekeeper playing a flute was infamous in that respect - he was imported from somewhere up north specifically for the photo session stunt.
There's probably plenty of information out there on his equipment style too; but I don't have time to bother with that today.
The Amon Carter Museum does have some crown jewels of photography which actually empathize with people of the West, like the work of Laura Gilpin. But I get the impression that Avedon was a diecast New Yorker all along, hunting down photo specimens as if he was bug collecting, seeking or downright fabricating NYC stereotypes of the West, as if Texas and the plains Sates even qualify to be accounted as part of the West.