| Evil Lincoln |
I suspect that the name-dropping of Janderhoff had more to do with the state of Golarion's development at that time. Varisia was finished, but the original Campaign Setting book was not yet released. For the APs (and APs were the biggest thing around the time PF6 dropped) I think they just wanted the iconics to fit into Varisia neatly since they were running 2 more APs there.
Mayhaps if the backstory were released today, he would be from Druma with no mention of Janderhoff. Maybe there was a good reason for him to move from one to the other though.