One of the other issues at Omaha (and Utah for that matter) was the US forces
were somewhat skeptical about the usefulness of the special vehicles that the British and Canadians used. Other than DD tanks and armored bulldozers they didn't use any other specialized vehicles. One that was quite effective on other beaches and I think could have been useful on Omaha was the AVRE with the Petard mortar nicknamed the 'Flying Dustbin'. They were great at destroying concrete bunkers, machine gun emplacements, etc. I think that could have been very effective at neutralizing machine guns that were so deadly at Omaha Beach. That's the benefit of hindsight though.