You know, at first I thought you were just being silly. But then I made a list, and I realised...

every city-state has 3 combat classes (Limsa was short on this until the introduction of Rogue)
every city-state has 1 Gathering class
every city state except gridania has 3 crafters.

This honestly just... completely surprised me, as I never noticed it before. I guess that's the cost for being the best looking nation.