That's more a question for rhombal, but I would THINK that they'd be separate fandoms. I mean, I can talk to you about Star Trek TNG or Reboot but don't know the first thing about TOS, and I'd consider them all complete separate. Same with Doctor Who and Sherlock. It's not like, say, bandom, which is comprised of a ton of smaller factions under one fandom, but they all intersect. The ones you mention would have to be separate. IMO.