Well, do you? If you were reading a book (about comics, say), and the author were to throw in a reference to someone (Dave Sim, say) being a bit like Henry Darger, would you know what they were getting at? That's if they said nothing to explain who Darger was, I mean.
By chance, I do actually know who Henry Darger is, but I had thought he was a very obscure figure, and not someone you could mention and expect people to understand what you were talking about. Maybe he is a household name in that America.