Chamberlain was fucked. If he went with one decision it the results were certain to be bad. If he went the other it could have been even more disastrous. No one can say which choice would have led to what conclusion.
Even today it's hard to tell what was the "right" decision. Imagine if you lived then without the benefit of hindsight.
This is preposterous nonsense.
Germany in fact was VASTLY WEAKER in 1938, and its quite clear for any historian who has a remote clue on the military balance of the time that Chamberlain's decision was indisputably a massive mistake in retrospect. Going to war clearly would have made things a far shorter and easier war for the allies.
I don't think most people in this thread realize just how badly off Germany was as far as tanks go at the Munich Conference in 1938 for instance. A very large portion of their tanks at the time were the Panzer I, which was a very light small tank with thin armor and just 2 machine guns for weaponry. It was only useful against infantry and other "soft" targets. The other primary tank Germany had was the Panzer II. This was a tank which still had rather poor armor, but did have a 20mm gun, allowing it to at least serve the typical role that a tank is expected to. Finally Germany DID have some Panzer III's deployed by that time, but if you do the math as I just did, they only had around 55 or fewer Panzer IIIs already produced by the Munich Conference! You also had around 40 Panzer IVs or less that were armed and usable during the timerperiod in question. (You have to subtract the number produced that were never armed and just used for testing purposes.)
By contrast, Czechslovakia had some of the very best tanks in the world during this period. The Lt 35 was the primary Czech battle tank during the period. It had a 37mm gun and 25mm frontal armor, which was superior to the armor on every German tank including the versions of the Panzer III and Panzer IV which Germany had at the time. Its gun was capable of dealing with any of these tanks, and by contrast, the Panzer II would have had allot of trouble taking out an Lt 35 with its tiny 20mm gun. Czechslovakia had roughly 300 of these tanks during the timeperiod in question. Czechslovakia also had around 50 Lt-34s which also had a 37mm gun and some armor to fill out their numbers. All of these tanks outclass the Panzer Is and IIs which made up the overwhelming majority of the German tankforce at the time.
France actually had quite a powerful tank force at the time, with both some pretty new tanks, and plenty of reasonably capable tanks which were still better than the Panzer I & II, giving France both a quantitative and huge qualitative edge over Germany in this area. (In fact, an obvious reason Chamberlain screwed up so badly historically is the LT-35 tanks and Czech produced LT-38 tanks were a very major portion of Germany's decent tank force for their invasions of Poland and France, which happened because the allies gave in on Czechoslovakia.)
Fighter wise, Germany only had around 600 ME 109s, and they were all the "D" model instead of the significantly more capable "E" model that was so successful as of the start of WW2. They actually were rather clear inferior to the Hawker Hurricane fighters the UK had in service at the time, with similar speeds, the Hawker Hurricane having the edge in turn rate, (the German fighters lacked an actual edge in diving until the ME-109E) and the Hurricane having eight 7.7mm guns, to just four 7.92mm guns for most of the ME-109s in service at this point. (The Hurricane also was notably a quite durable fighter.)
France also had around 350 Dewoitine 500 fighters in service at the time, which were not that far off in capability from the mere ME-109D model, plus a number of less capable additional monoplane fighters. The key here is besides Germany's ME-109s, they were still stuck with some not very capable biplane fighters as of the date in question.
Another point to note is that the Czechoslovakian Air Force had around 500 Avia B-534s in service by the date in question, while a biplane, it was essentially the newest and best land based biplane fighter ever made, and it partially made up for its speed limitations with exceptional maneuverability. A key detail to consider here is that historically Poland's primary and most capable fighter had a speed actually 4 kilometers slower than the Avia B-534, and they only had about 130 of them when they were invaded, yet the German Luftwaffe lost at least 110 aircraft to these fighters before Poland surrendered. (And this was with the more capable ME-109E doing much of the fighting.)
Basically when you consider all the details, you're looking at an extremely unfavorable balance of forces for Germany as of 1938. You can argue Chamberlain was a fool who spectacularly miscalculated rather than a coward, but its very clear giving in to Hitler in 1938 allowed WW2 to happen the way it did historically instead of a localized European conflict with Germany losing pretty quickly. (In fact there was a real possibility that the German military would perform a coup and get rid of Hitler rather than actually go to war under such unfavorable circumstances in 1938.)