In my opinion, yes.
For me, Edd Byrnes is the worst SW actor ever seen on the silver screen. I've seen him in Payment in Blood, Any Gun Can Play and in Red Blood Yellow Gold, and he was so unbelievably bad!
He just doesn't fit into a SW. His look (his poor excuse of an Eastwood like quiff), his still Cookie-ish humour. I don't buy this!
His version of a westerner might be good in an episode of Rawhide, but not in a real movie or even a SW.