Well...my point wasn't that Chamberlain was complicit, but moreso that there is a tangled web of complicity.
There are plenty of less well-known individuals within the French government and command structures I could wave at too. However, I did find the linked information interesting, and would be more than happy to deep dive on it if you want to start a thread. I'm not sure this is the one to go too deep, but certainly I would say that any suggestion that Chamberlain is responsible for WW2 due to an unwillingness to stand up to the Nazis is completely overblown, which I think you'd agree with.
Weirdly, perhaps, I've done much more of a deep dive on German arms/armour and production that on the Allied one. So at a broad level I wouldn't dispute what you're saying about Allied preparation, and I know the RAF in particular made good use of the extra time. French improvements were somewhat negated by their unwillingness to couple their improved position on paper with improved strategy, their willingness to fritter away their best units in small groups to bolster their worst ones, etc.
However, I think you're overselling German preparedness. You mentioned 5 panzer divisions being available in 1938. Technically, that's true, but the fourth and fifth panzer divisions weren't established until late '38 (November). Further, the personal for those divisions included large number of men from the Sudetenland, so talking about them as a viable force prior to that annexation is misguided.
Looking at the divisional preparedness further, it's worth noting that the vast majority of tanks in the five tank divisions by the end of 1938 were Panzer I and Panzer II tanks. These were next to useless against enemy tanks. It was actually German combined arms operations (including air force and artillery) that carried the day in France, rather than the sheer power of Panzers.
By the end of 1938, Germany had a nominal strength of roughly 3500 tanks (of course, not all were operational, but let's go with that). Of that, only about 10% were Panzer III or Panzer IV models.
In terms of air preparedness, there was a lot of messaging from the Luftwaffe indicating their superiority to all other European air forces, and the ability of the Luftwaffe to force Britain out of any conflict if required. However, Goring in particular was full of crap, and was playing internal politics to get more of the overall military budget.
Further, while the Luftwaffe were quite revolutionary in terms of their close support actions in Poland, and their integrated combined arms offence, it was as much accidental as planned. Goring in particular still favoured strategic bombing over tactical support, and the weather in Poland impacted on the initial invasion plans by the Luftwaffe. The engagements involving air support went so well that this tactic was left in place for the remainder of the Battle for Poland (basically - I'm oversimplifying here). This was made possible by the obsolete equipment of the Polish air force, and the inability of the Polish Air Force to mount a credible defence over time. Ground forces overrun enough of the Polish infrastructure that they ended up withdrawing considerable numbers of aircraft from the country entirely, further reducing opposition, and allowing Ju-87 dive bombers to swan around as mobile artillery. The reputation of that aircraft was enhanced beyond capability by a conflict where the Germans had complete air superiority, but the Stuka was not a credible weapon in a war setting of contested air superiority.
The Germans weren't ready for war in 1938. They weren't really ready in 1939, truth be told. But they were ready for a localised war, and they had convinced themselves that they could use a mix of politics, terror and actual armed capability (particularly aerial) to keep it localised.
I'd have to think about the Russian angle. But I agree that the Treaty of Versailles was a major contributing factor in the rise of the Nazis, and the move of the Nazis to initiate WW2. It was punitive in a way that didn't help stability at all, but it was also punitive in a way the German people were never going to be able to accept. For all of Germany's faults, there was plenty of shared responsibility for the commencement of WW1, but it was largely they who bore the brunt of it.
I suspect...but will obviously never know...that Hitler was looking for loose ends regardless of whether they existed, and would have manufactured them if they didn't. For all the way things are portayed now, the rise of the Nazis didn't fix the economic woes of Germany. What they did do was re-establish a strong national identity. But Hitler knew he needed more than that to fix the economy. Which is the main reason he was upset after Munich. Whether or not they were really ready for war, he knew they'd need access to Czech economic strength, along with various other items of consideration, be it Lithanian ports, or the Danzig Corridor. He would have 'stopped' only when German economic power was established. And one can only wonder if he would have stopped then, since at that point they would have been truly ready for war.
It's an interesting angle. It's also worth remembering that each of the capitalist countries had their own independent ideological forces to contend with, whether that was Mosley's fascists in England, or communist party operatives, or republicans in Ireland, or...
None of them operated in a vacuum, and the policies of individual countries could be as influenced by smaller domestic ideological conflicts as major international ones.
