Whilst it is true that Britain tends to glorify its great military disasters more than it does its victories (charge of the Light Brigade, Dunkirk, the Glorious Glosters etc) you are being overly harsh on the Brits.
The British were no dumber when they first came up against the Germans in WWII than any other nation, the French, the Russians and even the Americans (Kesserine Pass) all got their asses handed to them on a plate when they first encountered the tactics of the Germans.
The point is whether the generals learned from their mistakes, and despite the caricature of British generals as all being stuck up know-nothings the fact is that they were quick learners and generally tended to win the wars they get involved in, even if they did stuff up at the start.
You may be right about my harshness about Dunkirk. I should look further into that development.
But even though Monty was a hero in North Africa, he was a disaster in Europe with his instance on his way, like the pitiful Market Garden (more head up the a$$). By war’s end, Ike could not stand the guy. Thank God for the Americans and Patton who out-blitzkrieged the Krauts.