Heck, we had
three separate Sherlock Holmes series running concurrently not too long ago, each with their own continuities. Somehow the general public didn't get Robert Downey Jr and Benedict Cumberbatch confused, nor wonder how Lucy Liu fit into the movie series.
Although I do remember having to practically twist a friend's arm to get them to check out SHERLOCK because they objected on principle to the idea of a modernized Holmes series because it wasn't "true' or "respectful" to the original canon. (Needless to say, they loved it once I forced them to watch it.)
Ultimately, who cares if a prequel series is "pure" enough? Purity is overrated.