Oh, please, don’t be so snobbish. Anyone who has directed Laurel & Hardy, W.C. Fields, Bob Hope & Jerry Lewis is pretty damned good - as well as very successful.
And Murder, He Says is plenty funny despite being
oh-so-tasteless.
He was certainly at the right place at the right time. Fields’ films were notorious for being badly crafted and Marshall didn’t even direct the best of them. Fields did much better work at Universal in later films. His Lewis films are also fairly obscure. The Ghost Breakers is fun though. And the story was later revived for Martin and Lewis’ ‘Scared Stiff’.