After Czechoslovakia as guaranteeing peace “in our time”, or declaring war when Hitler took Czechoslovakia. There were many more than those 2 options. Like saying nothing about Hitler’s trustworthiness. Which might have led him to pursue an agreement with the USSR to guard against further nazi aggression, rather than taking Hitler at his word.

Churchill was not about to flout the failings of his predecessor while uniting his country against an existential threat. And in any event he did not have the full benefit of historical perspective we now have. So that part of your post is irrelevant imo.