Can't agree. Bon Scott is a nifty singer and all, but his voice is clearly geared towards sleazy hard rock and not thrash metal
Shows how little you know of singing.
You're kidding right? Vocalist and singer are synonyms, there is no difference between being a "vocalist" and "singer" except for vocalist usually more specifically refers to jazz/pop groups, but nowhere near always. https://en.wikipedia.org/wiki/Screaming_(music)