So I did some quick research on Octopath Traveler and came across this
http://www.shacknews.com/article/10...e-bonuses-and-skills-list---octopath-traveler
I then noticed there are some huge differences between stats with each class and subclass. Apparently there are also 4 rarier classes that the player can get later on in the game still at these "shrines" but with the requirement of having to defeat more challenging bosses.
I also read in Octopath Traveler the subclass stats don't affect stats growth and you can't change main classes only subclasses like you said.
I also read that when you unlock passive subclass skills and then swap subclasses, the same passive skills remain unlocked no matter what. Woah! That surprised me.
But with your ideas, I would agree with Eschaton that it'd be best to have "main" classes/subclasses unlocked early on if you go with that approach, since you'll want them to balance out in a way that each has it's own advantage and disadvantage while they still each remain useful in certain areas of the game.
However, with Octopath Traveler it looks as if all the classes are useful but with each main character class some subclasses aren't advised. So some subclasses are not as good when compared with pairing with other subclasses, yet with all 8 actor classes all subclasses with the 8 of them together still have some use, and I think that would always be the case even with a good subclass system, since they can be tricky to balance out.
If you decide to do the shrine thing though, or your expanded guild verison of it, then that would naturally lead you to a game where a lot of locations are unlocked near the beginning.... and I have mixed thoughts on that.
I'm sure it can work somehow, but you'd need to really think everything out ahead of time.
My thoughts with a way around it is to have all these main locations for swapping subclasses unlocked early on in the game with a clear manual on the different advantages per class for the player to get used to the system, and keep the shrine/guild locations short distances from the other on the world map, then have real/extra locations in the game after that where most of the game takes place while still making it easy for the player to change subclasses.
The main problem I have with the "guild" system is, if it's not easy to get to each guild and meet the requirements to change subclasses, then it'll be difficult for the players to switch and change them with ease, so if they make a mistake they'll be greatly punished for it, and I'm against that outcome without a quick solution to fix it....
Could you also elaborate on what a "guild test" would be?