I don't know. That's really subjective. What is a tag team? Who isn't?
Just being able to form your own seems fine. There has been so many combos over the years, anyways.
Just use legitimate teams and miscellaneous teams that had a significant angles/title reigns. There's definitely enough for a 12-team tournament.
Miscellaneous teams would be teams like HBK & Diesel, Two-Man Power Trip(Austin & HHH), Rock & Sock Connection, Big Show & Jericho, etc. They weren't full-time tag teams and lasted less half-a-year but had enough significant angles and reigns to be picked.