" The radical leftist view of him is of a heroic man who tried to free the slaves through an insurrection..."

uh, yes. Cuz its true.
Hence why I said it's true.

I am not familiar with this claim. In my experience, those who uphold Brown also uphold Turner.

Please share with me some sources of people on the left who are wavering on Nat Turner. Or even one source documenting your claim will do.

If you can't provide any example, please note that. OK?
I also haven't seen that either.

But the mainstream, non-left view (what I was taught in school) of Nat Turner is more negative than that of John Brown.

I think radical leftists are fairly consistent on it though.