What are the popular theories of Miri's earth & the one with the Comms & Yanks?
One thought: A civil war with the Q, where there literally tossed around worlds, and brought some to the Trek galaxy.
Perhpas Starfleet has some knowledge of it, but will only share it with Captains if they find an alternate earth (like the Enterprise did).
Here's a question -- are there alternate Vulcans? Or Romulus? Or ...?