Villagers seem to just take whatever job regardless of what stations are nearby. In my case, I cured a zombie villager and had a lectern next to him, once cured, he instead became an armorer. Although none of the blast furnaces were close by, I broke any that were around 50-70 blocks nearby and he was still an armorer. This also seems to affect creative, as when you spawn a villager, instead of being a default until a work station is place (lectern, blast furnace, etc.) they just randomly pick a job. I also tried curing zombie villagers (6 zombie villagers) in a new flat world with some lecterns placed and none became a librarian. (3 armorers, 2 weapon smiths, and one farmer.) if you want to reproduce this it seems really simple, either just spawn villagers with an egg and they will pick something random regardless of workstations. Or cure a zombie villager with weakness potion and a golden apple, place a workstation nearby (in my case I used a lectern), and watch them ignore the workstations and pick a random job. This is very unfortunate as I just lost my fully enchanted netherite armor and wanted to get a librarian with mending and I couldn’t even make a librarian. Thank you for reading this.