From: Bedfordshire UK
I give Monty props for Normandy, but it seems to me he rather dropped the ball in Market Garden. Even Brooke felt he made a mistake in not securing Antwerp.
Monty also never seemed to understand that the United States wasn't going to reduce itself to a mere appendage of the British army at a time when the USA was contributing the overwhelming amount of forces in Western Europe. And Brooke and Churchill both tended to encourage him in this delusion; Monty had no political sense whatsoever, but they should've known better.
Everyone dropped the ball in late '44, thinking that the Germans were beaten and that the War would be over that year. The Allies were still being supplied through one Mulberry (the British) harbour, the British PLUTO fuel line and with extended supply lines, it wasn't just Monty, everyone came to a stop at, or near, the West Wall. The US Army had effectively lost its independent supply line into Normandy and was reliant on the British beachhead for landing supplies, a source of much friction.
Many generals lack political sense (which, however, may be a good thing in a democracy) and lose sight of the overall goal. Clark going for Rome and not killing Germans, MacArthur wanting to Nuke the Chinese, etc.. It was no delusion that Overlord could not have succeeded without either the British, as well as the American contribution and whether a quick strike into Northern Germany might have ended the War quicker than a strike into Southern Germany. The Broard Front approach was the neccessary political solution, but was it the best military solution, I suppose we will never know.
A lot of the frustration of late 1944 has been heaped on Monty, but there was no easy solution for the political and military difficulties the Allies encountered after September, with all forces (US and British) running out of steam after the huge advances following the breakout.