So I'm pretty sure this is a question that gets asked a lot because, well, whenever it comes to History, Godwin's law is in full effect.
I was watching some behind the scenes stuff about the New Star Wars film when they got to talking about the new bad guys, the "First Order". They said that they were inspired by the question "What if all those high ranking Nazis that fled to South America tried to get together once again?" Well their end result plot wise was essentially the Empire going the way of "What if Neo-Nazis had actual resources and older Nazis to guide them in establishing a state?"
So this got me wondering, I imagine many high ranking Nazis never actually made much of an effort to meet with their former peers--after all that could lead them to being found quicker--if they even knew that others had escaped to South America with them.
While I doubt they'd be really keen on the whole "National Socialism" thing given their predicament and how well it worked the last time (not to mention they were likely not as fanatically devoted as Hitler and some of his closest peers were if they fled and went into hiding) is there any record of if they had any plans while in hiding, or attempted to influence the politics of their new countries?
It's an interesting concept, and I'd like to know more about just what many of them were doing while in hiding.
While you sort of seem to answer the question on your own (regarding how logically unlikely it would seem that they'd do so), I do have some information which would be of interest to you. Hopefully you won't mind that it deals with the Middle East as opposed to Argentina, even though I can tell you that in my research into post-war Nazi refugees in Chile, I've had very little telling me that they would even have tried to influence the politics of their new countries beyond being the rallying point of neo-nazis.