I think it's a definitely a system like this, but just a few minor nitpicks. (Sorry that this comes across as critical, it's just the ones I notice standing out)

I feel like starting with NE and 100 SB point gain is a weird start point, when 6 hits of 1.1/3.5 of a single element seems clearly the base for most of the abilities. It doesn't affect your analysis that much, but it's an odd extra step to include.

There's also clearly 7 hits long cast time at 2.85 each as a Witch starting base, and 5 hits at 4.95 either group or single & heal 1000 as a summoner base.

In addition it's clear that for example, they value one extra element as not quite being worth losing an extra hit, but gaining multiple elements is. Bartz, OK, TGC, Rydia for example, gain multiple elements but lose one hit, while Squall, Seifer, Terra lose a hit to only gain one extra element, and get an extra thing added to bring it up to strength. Seems like it would be +1 for one extra element, and +2 for two or more additional elements, while losing a hit is -2.

I think that means there's some that definitely seem out of place here. Rinoa's for example being listed as Neutral seems wrong, as it's right above Y'sholta's, and their multipliers are identical with no other differences yet Y'sholta gets 4 elements and Rinoa gets 2. I'm also not quite sure how you've arrived at Prompto and Balthier's being so good, as they gain an additional hit but at the cost of very low multiplier per hit that I'd argue is a clear two steps below normal.

You've also got Exdeath listed as Neutral but Pecil listed as -1 when they have essentially the same ability? They seem to have established a precedent that hybrid is worth losing a hit. Certainly there's no way Exdeath belongs on the same tier as Vincent who is comically over budget, getting 6 hybrid hits of normal strength while Exdeath is 5 hits. A bit unsure how Rikku is normal while Faris is +1 as well.