Yeah... no. This is a pretty bad idea. If it had been "let's try to expand each class to have two jobs, and maybe make up classes for the only jobs, which then could have a branching path" that still would have been bad. But "let's combine jobs regardless of shared weapon, thematics, or anything else with only the loosest of justifications"? I'm good. Summoner and Scholar, if anything, should be split apart (and hopefully they're working that out if it can be done) and share less with each other. They have very unique themes and such going for them and could stand to split more with less mechanical commonality.

In comparison to them though almost none of these jobs have anything in common. Mechanically they are all over the place, their weapons range from "kind of in the same ballpark (Paladin/Dark Knight)" to "they have zero overlap" (which is most of them). Thematically these jobs are all very different from the ones you're trying to pair them with, and even without seeing it Geomancer is an entirely separate job from White Mage, the two have next to no common ground in terms of themes. It's just... a mess. For no real reason either. It doesn't add any sort of positive gain except spending less time leveling things, but that's not really a good justification. You could just as easily solve that with some sort of bonus exp system where you get EXP for completing things you can spend on any class. But really, you should be playing the job you're leveling, so it's hardly surprising they don't do that.