I’m not sure if the idea was ever seriously considered. I tell you what. Read this book.
http://www.history.army.mil/html/books/007/7-1/index.html
The answer is in there. Somewhere. My guess is it never occurred to Ike and was never suggested. Devers’ army came up from the south. He was not in “the club” of the generals who came out of Normandy. The United States was way more political than is widely portrayed. There was no way Bradley was going to give up Patton’s army, and Ike probably never considered it.
Look at pages 311-316. It looks like a variation of the henkster plan was suggested to Ike in November. By Monty. No wonder it got not no traction.
Thanks. I’ll take a look-see.