@KamiKira00 No it wasn't. Or, well, let's rephrase that.
(I know it's a 4-month old comment, but for future readers).
HE made a hypothesis that he unlocked 3 classes as Villager hit Lv5, but it wasn't "clearly stated" by any knowledgeable source, be it book or character. It did seem like he's right, but then again Warrior and Swordsman basically are "fighting", which is what he was doing, so he might still be technically wrong.
Also, he made a hypothesis that MAYBE he would unlock more at higher levels, but he doesn't know, so...he's just going for the ones that stack stats to make dungeoneering easier.
I guess he could make a point of each change, but personally I think there's enough explanation on most things.