0-level retainers don't last long (but they aren't dying)!

How do you like my click-bait title?

For real though: It seems to me that the OSE rules for 0-level retainers imply that they would gain a class after the first sortie into adventure. They get 50% share of XP, they receive XP once they return to a safe haven, and any XP they gain will covert them from 0-level to a 1st-level classed NPC. At which point they want more money or a share of the loot. Does this track from how you interpret the rules?

I could see stingy PCs leaving a plethora of disgruntled, newly raised, 1st level ex-retainers in their wake...

Edit: I might have mis-emphasised the treasure share part of the question. I might also be confounding the rules about retainers from Carcass Crawler zines. In anycase, my main question was about the somewhat 'automatic' change from 0-level to levelled retainers. In the sense that if they go out as a torch-bearer they will get at least 1 XP pretty darn quick, and gain a level. So no retainers will stay 0-level for very long. That's the part I was looking to confirm. Do you agree that's what the rules imply?