Disrespectful to the tens of thousands of french soldiers who fought bravely and well to let the British retreat (or run if you're a Frenchman) from the beaches of Dunkirk.
What if Hitler had never come to power? These are all so far fetched scenarios that they're almost pointless. I only find such hypothesis interesting if there was any immediate likelihood of an event eg in this context, what if the army had not been saved? The RAF had been defeated...but to...
It's not an especially interesting 'what if' because the Germans did try to invade. Only they lost. Air control was the first stage of the battle for Britain. So we know the result. The answer is, Britain would win. Because we did.