I mean, yes, Iran is Aryanshahr in Old Persian or something like that.

Nazis formed their ideology in a bit of a barbaric time in linguistics, where grouping Germanic and Indo-Iranic languages and attaching Armenian to the latter was kinda normal. And when such action allows you to attach your axe-swinging barbaric ancestors who conquered Latin-speaking and Celtic-speaking peoples (incidentally your current chosen enemies are mostly Latin-speaking) to something similarly ancient, and also raise from the same civilization level with Slavic peoples to being a level above them (and your another chosen enemies are Slavic-speaking), and you live in the middle of XIX century when everybody did crap like that, and not having mythologized new nationalism for your monarchy is not an option, because you are being bitten by angry revolutionary students and the vague possibility of Austria becoming center, so you have to disqualify most of its empire as inferior, you just do.

Then Nazis did a few smaller steps at treating that by then obsolete neo-Pagan heap of bullshit like something serious.