Linear, linear, linear

[Shurrikhan]

If SE came out with a BLM talent tree tomorrow that had several passive skills and two active skills that we had to choose from while leaving all other BLM skills unchanged, would that... not be additive? I'm a little confused with what you're trying to say here.

Again...

:: Whether some means of providing actions is additive or not will depend on your frame of reference. If you compare it against simply not having that means of actions, then yeah, it'll look additive; but if you compare it against what could have taken its place, or against not having any such limitations (not forced to give up A and B to take C but can instead take all three), then it won't.

If you added it to what we have now, yeah, it'd be "additive". The choice is between 5 skills (no customization), or "Pick 2 of 5 skills".

One (no "Customization") gives BLM 5 skills, the other ("Customization") 2 skills chosen from among 5. Which is the more "additive"?

It's similar to the question of "Assuming balanced effort-per-reward, so that players aren't obliged to simply swap to the highest output for what amount of effort they're willing to put in... Should SMN have a higher skill ceiling?"

One approach says that every job should have a pretty high skill ceiling, and people should be free to optimize as much or as little as they like (just give them everything). The other says that each job should have a different skill ceiling, but have their output ceiling vary accordingly, so that whatever they're not interested in dealing with is out of sight and out of mind (customize their gameplay to just their preferred slice). [The third choice is just to have intentional imbalance, as would affect the largest group of players, rather than just the occasional far easier job being less than ideal for speedrun parses.]

Here, too, you have the choice between customization allowing for varying amounts of complexity (which then, if balanced, affects output ceilings), or simply different types of complexity. But regardless, you're still saying, relative to everything that would seem fitting for, say, a BLM to have access to, you're taking only a part of those remaining prospects. More is designed than can be used at any given time. [This is much like how we can't use the kit of every job at once; jobs are, themselves, customization, after all. But here you're now taking a segment of a segment of available gameplay -- an increasingly narrow part.]

[kpxmanifesto]

One (no "Customization") gives BLM 5 skills

I mean, that would do away with the whole personal expression and customization bit again which is one of the major draws of being able to choose your talents. I would opt for the "pick 2 of 5 skills." It would still be additive and would give the player the option to customize their playstyle. Plus, depending on how SE balances it, being given all 5 skills could result in power creep.

[Shurrikhan]

I mean, that would do away with the whole personal expression and customization bit again which is one of the major draws of being able to choose your talents. I would opt for the "pick 2 of 5 skills." It would still be additive and would give the player the option to customize their playstyle. Plus, depending on how SE balances it, being given all 5 skills could result in power creep.

Again, I'm fine with either one as long as the "pick 2 of 5" doesn't over-specialize jobs in our current context.

I just slightly prefer greater job versatility over that, in part because it's sort of a direct rebuttal to tendencies to simplify jobs to a mere thin spread of gimmicks atop a basic role template.

Well, and I like for different fights (and, up to an equal degree, compositions) to influence how I play a job therein -- rather than just swapping my talents around, putting the new actions in the old's place, and playing more similarly between fights (in terms of button-flow and strategy) than I would if not for those load-outs / constraints existing.

And, if we actually changed that context so that it was expected that everyone multi-jobbed anyways, and that grind-barrier (and perhaps gear-lockout barrier) to multi-jobbing was reduced, I wouldn't even mind some jobs having a pretty hefty utility advantage in this or that fight. I just don't want to see any advantage in terms of basic category of capacity (this job is the AoE god, that job the best at ST [in a raidbuff-packed party], etc.).

Edit:
As for power creep, if those skills are ones that would normally be split up across different "specs" or parts of a "pick X of Y" selection, they're generally going to be at least somewhat anti-synergetic, much likes stances and spenders. You can do A or B, not both. Which is (unless the choice is always obvious, though then those actions couldn't possibly have been in competing builds).... customization, to the same degree that choosing build A or build B (where in a particular context [skill, composition, coordination], one build may be superior).