What epistemic value does "similar rhetoric" have? The relevant question is whether something is true and/or defensible. Identity does matter, to some nations and historical contexts more than others. It is silly to project the particulars of the US historical context to the rest of the world.
The exact same argument would apply to the racial politics of Nazi germany or the Jim Crow South.
That doesn't answer the question. Identity does matter. Because Nazi Germany came to the wrong conclusion does not invalidate every premise used in their justification.
What was wrong about their conclusion that isn't equally wrong about the conclusions of these other white nationalist parties?
It's pretty clear to me that all these parties have racial animus (not ethnic identity) as their core, and we all know where that leads.