My impression of Monty is that he was not a bad general, but he was a bad person.
But Monty did not seem to have had a good grasp of how to fight a war of maneuver, at which Patton excelled. Monty certainly didn't "dash" up the Arnhem road in the Market Garden fight. He absolutely would have been the wrong commander for the one big push on Berlin plan he and Churchill kept pushing.