"The conclusion I came to (you can read this in detail - the first chapter is available on-line from my website) is that the Brits would have decided that:
1. War with Hitler was inevitable
2. Trying to stop the forthcoming German invasion of France was too risky."
Tony, I haven't read your book, but from what you listed here. You missed an few important points that Britian could of done before 1940.
First Germany was weak in when it marched troops in the Rhineland, the Brits could of done something at that point and it would stopped Hilter. Or in 1938 teh Czechs hasd a very powerful army and lost of tanks and it was ready to fight if support had of been there. If Britian had the knowladge that this Historian had then would known that it could stop war before it started. Or if it waited until France was invaded, it would known that the german victory was do luck in most part and surprise. without surprise the the germans couldn't have won as quickly if at all. The France had more tanks and more planes, and could planned for an attack. As it was the Germans were close to being stopped, if the attack had lasted a few weeks it would of run out gas and ammo.
Well, we could debate this at length! The first chapter (which you can read) does give the British thinking behind their choices. basically, they want to make as few changes to what actually occurred as they can, because the moment they start to depart radically from the historical time-line, they lose their advantage of 'foreknowledge' and will be groping in the dark like anyone else. So if they tried to stop Hitler in 1936 or 1938, no-one knows what the outcome would have been.
However, I am happy to concede that there were all sorts of possibilities. All I could do was choose some which were justifiable and internally consistent.
Tony Williams: Military gun and ammunition website and discussion