Given that the Nazis probably could have accomplished more if they'd had slightly fewer crazy ideas, he does not appear to support his own claim.

But there is an interesting question, which is how many fewer crazy ideas would be required. I mean, arguably if the Nazis were completely reasonable, it's unlikely that they'd have been all that successful either. They had to 1) appeal to a certain contingent, while 2) scaring the crap out of everybody else. Arguably, having a certain amount of sheer batshit crazy ideas helped with both... whereas being merely mildly eccentric and power-mongering probably wouldn't have helped.

IOW, it's likely difficult to separate the Nazis' results from their irrationality... even if that just means they were being rationally irrational, so to speak. (Of course, making a commitment to being scary-crazy as a deterrent/threat strategy means you're likely to still be quite crazy when you actually have some power.)