Nice, I like this kind of discussion.

So 47% of Jobs are combo based, 21% are healers (go figure), so 68% total. The other 32% (1/3rd) are either proc based (1/6th) or freeform/other (1/6th).

Combos should probably be broken into "limited" vs "expanded" as SAM and DRG have rather...different...combo sets than NIN or MCH, etc. That said, not every one is created equal. MCH has a 1-2-3 combo, but a lot of non-combo GCDs that are worked into the rotation aside from the filler. Contrast NIN, where most of its non-filler gameplay is oGCD, not GCD, based, or Tanks like WAR where the majority (I think?) of its actions are spent on its 1-2-3/-4 button presses. Also, PLD's combo sort of branches, it just does so in a different way. You can order the branch any way you want, so to speak. GNB also has special mention since it has an entirely separate combo, though whether you want to chalk that up to "just burst" or not...granted, so do PLD and WAR, but their alternates are just the same button several times (GNB's has a bit more nuance than that...)

In any case, that sounds about right. 1/6 proc, 1/6 freeform, 1/5th healers, a bit less than half combos. Though we'd have to do a survey of players to see what people actually like to see if this matches that percent or not. That is, do the majority of players WANT to play proc based Jobs? Then they're underserved. But if it's only around 1/6th, then they are well served. The issue is more like I said about options across roles.

Right now, for example, there's a simple/straightforward option in each role (WAR, WHM, and SMN). That's not a bad thing, as it means people that like that sort of gameplay have options in each role. Note the proc Jobs are all DPS, two of those are Ranged Phys, and all three are heavy support kits (even RDM). Not only are the options for support DPS all taken so people who don't like procs don't have one, people who do like procs but want to do literally anything else don't have an option.

So it's less we need more proc Jobs and more we need the proc Jobs across more roles. Maybe DRK's inevitable rework could be to be proc based to get it out of WAR's shadow, for example, and AST being proc based would...make sense given the fortune/fate element of the Job.