Plainly not, given where he is now, following him breaking his word. He’s plainly a poor strategist as he’s unilaterally elected to involve himself unnecessarily in a war that has crippled his county economically, caused it to be isolated and greatly reduced in its national standing, has led to the death of hundreds of thousands of young men in a country that is facing a demographic time bomb in a generation or so and has caused NATO to expand, which was the express aim of the invasion, despite his pitiful attempts to reference neo-nazis. He’s clearly a shit strategist, his judgement clouded no doubt by having too much power for too long.
Whereas Chamberlain most likely bought us enough time to make it more likely that we weren’t completely overwhelmed when we went to war with Germany. And it was unquestionably a very close run thing, so every month would have counted, most likely. This enabled us to stay into the fight until happenstance intervened and Japan went postal, and Hitler got distracted by his innate suspicion and hatred of the Slavs and communism. By any objective analysis we’d have been fucked going to war in 1938, and there would have been much less appetite domestically at that time. A final line needed to be drawn to make another war palatable to the general public after what had gone on a couple of decades before. So, overall, I think there’s a strong argument the Chamberlain made an effective strategic call, given the circumstances.
So drawing a parallel between broken promises and strategic competence is a straw man argument I’m afraid to say. It’s a wholly separate argument, and one for which you have justification for advancing, but not within the realms of this subject which was one of competence, not morality.