But just as that certain other US politician, he mostly came to power due to complacency and collaboration by more moderate nationalists and conservatives. And while the mythos of Hitler was immense, his draw not to be underestimated, without people like Goebbels, without the people hungering for just about any populist figure that enabled their own conspiracy theories, he would have been just another charismatic figure.

Let's put it this way: If you went back in time and somehow turned Hitler into a communist would that have led to the KPD being voted into power by the enabling act? I seriously doubt it, he was an exceptionally skilled speaker and decent political tactician, but he was no hand that pulled the strings of fate on his own.

Well, history is actually full of those guys. Successful enough to actually conquer territories? Much less, but still quite many.

It is both.

I used to think the Great Man of History idea was silly. Clearly, it was a about a complex set of conditions that made somebody like them inevitable.

Then I worked for a few CEOs, good and bad and realized that, even in a company of thousands, the vision and charisma of one man makes all the difference.

Now, I think I see it like great plays in sports. It is the whole team, and the other team, and an uncountable number of factors ( bump in the turf ) that setup the conditions for that perfect shot. Once conditions are right though, you also need somebody capable of capitalizing on that moment and making history. Perhaps the most important element is that history making player. You still have to put them in the right spot though and a lot goes into that.

True, individuals aren't completely without influence of course, it would certainly re-roll details of what exactly happens, which could turn out significantly better. Unfortunately it could also be worse.

Also, there are limits to what can be achieved with it. For example, even without Hitler, to achieve a successful socialist movement in Weimar Germany, you'd have to do a lot more, Hitler was raised into a fascist demagogue by organizations active long before him, and their foundation was so rooted in the sense of revanchism and the rampant conspiracy theories drenching with antisemitism in Germany at that time, I genuinely think he was not important enough as a rallying figure to have tipped the scale, it was weighted heavily in their favour to begin with.

Keeping the SPD from hiring and strengthening the protofascist Freikorps alone would be more influential than killing Hitler, for example.

Indeed. Some people wrong place wrong time completely alter the course of history from that point forward.

Go back in time and try to flag down Archduke Ferdinand's motor carriage only for the driver to get freaked out and go down the alternate route right to where Gavrilo was trying to get to the original route but was running late because another time traveler delayed him...

Personally, I'd think that would have resulted in a very different World War in the following years, but I am genuinely of the opinion that it was unavoidable. The conflicting imperialist interests were getting more and more tense, and Bismarck's web of alliances to keep the peace had not only already failed but had become impossible to maintain (due to those ever more rising tensions)

Nuke it from orbit. It is the only way to be sure.