The capacity to modulate which you imply that Hitler would have benefitted from was incongruent with the personality necessary to rally Germany to that stage in which he might have chosen modulation.

He would have had to change his stripes.

His sense of accomplishment was off the charts. He had come to dominate a nation and a region and that urge to dominate the entire world came with it. He was possessed.

I can boil that down to one line of text... Drunk with Power

Yes, Hitler was a nutjob. No doubt. That doesn’t mean a nutjob was a necessity to bring Germany back from the demilitarization and economic destruction caused by WWI and the subsequent Versailles treaty. A more rational leader could certainly have brought Germany back to its rightful place among the great powers. It might have required a war (although the French and British were very reluctant to fight and only did so when it became clear that Hitler wasn’t interested in simply justice for Germany but rather in hegemony). A war doesn’t imply the necessity to commit genocide, though. Even if it was necessary to have a leader hell bent on world domination to rescue Germany (which I deny), it still wouldn’t have required an insane leader who promoted an evil ideology that treated most others as subhuman and led to genocide. There have been plenty of leaders who aspired to wide-spread domination WITHOUT the genocide - Alexander the Great, Napoleon, etc. The thesis that genocide was required to bring Germany back from Versailles just doesn’t hold up.

Leopold II of Belgium