I think the point is that if Hitler started the war, say, 5 years later, then he would have had time to develop these things properly.
Of course, if the US have developed the A-bomb in this time then things might have been different. Maybe.
That makes more sense, but then again it doesn’t, since the British jet development programme was at more or less the same stage as the Luftwaffe’s in 1943- they just didn’t have to rush the Meteor into production like the Germans did because air superiority over Britain was already established.
If there was something Hitler/Germany should have done differently, it was scaring off/expelling all the Jewish physicists from the University at Gottingen; he could have had his own atomic bomb as early as 1939.
^
While the exile of Jewish (and other scientists who had little time for the Nazis) was certainly a factor, the Manhatten Project needed resources and infrastructure that Germany never had.
The real “Of course,” is that many of these things weren’t being considered in 1939, or else were being considered only in esoteric labs and pitifully small design offices. That is, these potential superweapons weren’t even in the strategic calculation in 1939 when the was started. Donitz wanted to hold out and start the war in 1941, not because he wanted to wait until advanced uboats like the Type XXI were available, but in order to have a much larger force of basic, non-advanced Type VIIC boats. The Type XXI wasn’t even in the conceptual stages in 1939.
Without wanting to needlessly reopen a thread, I did find The Cranborne Report on wikipedia. If the cite is to be believed, it does corroborate what you mentioned there.
The Guy Liddell Diaries. backs this up. Liddel mentions several occasions when he, as MI5’s Director of Counterespionage, met his opposite number in Irish Intelligence to exchange information.