A cynic or conspiracy theorist would note a correlation between FMIC acquiring Guild and the published data becoming wonkier. They might also note FMIC's confusion about how the Guild "Anniversary" would be dated.
(Not that I think you subscribe to that idea, but "for the game"):
And a myth-buster would bring up the fact that the "wonkiness" period
really got rolling around '87 to my perception, with the introduction of the Gruhn model name changes. Just a viewing of the s/n lists themselves from '87 to '94 is revealing for the frequent model name changes.
Witness the overlapping in sequential years of the same build under different names especially in the transition from the F50 to JF65/ JF6512 family..and the corresponding spate of sightings of guitars from that period with discrepant labels, particularly the "GF" family, even though legit.
I suspect that not only was there internal miscommunication, but that the frequent changes of ownership and location didn't make record-keeping all that easy, either. That wonkiness period kinda seems to overlap the period from the Avnet sale to "who-was-it?" before the Gruhn consortium acquired the brand. I'm a little fuzzy there, might have the details wrong but the point's still valid.
So I think Fender did the best with what they had. Y'just gotta remember to take into account the limitations.