Actually, looking into it a little more, it seems Gretsch is a little more independent of a company (guitars is separate, but distribution is done by FMIC), while Guild is a wholly owned subsidiary. Similar to GM owning Saturn (mostly their own separate designs) and Pontiac (mostly just rebadged Chevys, mostly the same chasis'). Though the metaphor breaks down when considering that Saturn got turned into another re-brand of Chevrolet after 2003, and then went away.
Anyway, it would be much easier for Warmoth to get access/authorization to use Guild designs/IP, since they could just ask Fender directly.
So yeah, the Bluesbird, Polara, and lots of others: thems some pow'aful good options.