It's slang, who cares. Regionalization of words and adding individually meaningful connotations is common and normal in all language. Both 'Newbie' and 'Noob' are recognized words in the English language and any arbitrary distinctions you add or don't add to them are fine until you expect others to do the same, then you need to enforce meaning. Though I suppose that's what you're trying to do here, enforce arbitrary connotation to add distinction.
Though to answer your question, yes there are multiple iterations of the word without additional meaning that spawned simply because they can when you mix enough cultures together. To say that nub, noob, newbie, newb, n00b, and all variants must have independent definitions is desperately clawing for meaning when slang is just slang mang.