Oh sorry, didn't think the comment would go through after this long. I have by now have gone through every other mod I had installed one by one and figured it was just conflicting with them. I had written down which ones if you ever plan patching around them:
Bard Class, Royal Noble, Shiny Things, Stuffstuff, Beastmaster, Experimental Erotic Expedition Expansion / General Vanilla Rebalance (parts of the same mod but enabling either one of them allows rogues and rangers through)
But it still worked out, since I pushed it to even further restriction level for my own play. I would restart the game until it had a peasant in group, would immediately after tutorial send out the others to get kidnapped and abandoned, and treated non-peasant classes on stagecoach as just visitors and only the peasants as rare desperate adventurers that would be willing to join the village, especially after enabling cursed classes to dilute things even further. It was quite fun at the start having to carefully run through dungeons trying to fish gear upgrades while avoiding battles until another one or two would join. I even started generating AI art galleries to illustrate each character's journey/progression to really get attached to them and give them personality.
Would be cool to someday see the peasant tree expanded up to elite level without much power upgrade and with class change cost reductions pushed to the very end, since it eventually still becomes just an arbitrary roadblock to their real class and not much happening in between, since the whole tree can be cleared in a dungeon or two.
But thank you very much for making this mod. I would not have gotten into this game nearly as much as I had if not for it :)