SF complaints about being used as Rangers, was especially heavy during the Vietnam war.
I’m confused, do you want to use them as infantry, or you don’t want to?
I’m not aware of those complaints, during or after Viet Nam. SF’s were multiple force employers. Rangers were also, just in a different way. Towards the 72-76 push, there may have been some consolidation of line command, but not really enough to warrant any gripes. By the by, SF is not US Army Infantry. US Army Rangers are the US Army Infantry. All other units follow- Lead the Way.