We don't have to retcon it in, just make it a part of the story that there's some coalescing, coalitioning, and merging of similarly-minded groups.
Not neccessarily every similarly-minded group will fall into any particular coalition, so there's some room for oddities (like the Macross fans ending up with the Rockhounds, for example, or the Soviet/Federation alliance).
Have it be something that happens over time, not right away.
--
Sucrose Octanitrate.
Proof positive that with sufficient motivation, you can make anything explode.
Not neccessarily every similarly-minded group will fall into any particular coalition, so there's some room for oddities (like the Macross fans ending up with the Rockhounds, for example, or the Soviet/Federation alliance).
Have it be something that happens over time, not right away.
--
Sucrose Octanitrate.
Proof positive that with sufficient motivation, you can make anything explode.