They messed up big time with SMN/SCH. These are my least favorite combat classes and I've been putting off leveling them.

At first look, it seems like it would be a shame to do away with a fork/tree system that branches out, because it would seem like you miss out on opportunities of having similar but different jobs with a base class to tie them together.
But in reality when you think about it, you can just have similar jobs exist without having to tie them together with a base class at all, and just keep them completely separate. There would be nothing wrong with that.

An example would be the upcoming Machinist. At first glance It would make sense to perhaps tie it together with possible future classes such as Musketeer and Corsair. But really if you had all 3 of those as completely seperate jobs without anything tying them together no matter how similar they are... I don't see anything wrong with that at all. Some people might complain that it would be useless to have them exist if they're too similar, but I don't think I would actually mind it.