I know how it would work for the Jobs I've played at any rate:

For Red Mage, it would just be nice to have Riposte, Zwerchhau, and Redoublement on one button, like it is for PvP. How Veraero/Verstone and Verthunder/Verfire work in PvP maybe wouldn't cross over to PvE, nor Verflare and Verholy.

I think this would be a godsend for Dragoon; one button for Impulse Drive-Disembowel-Chaos Thrust, and another for True Thrust-Vorpal Thrust-Full Thrust. That's a reduction of 66% for their base combos (I don't think Wheeling Thrust and Fang and Claw would work well with this but hey, if you felt you could reliably tell the tooltips apart, maybe that'd be fine, I have them separated on my hotbars cause I'm a scatterbrain and need the spatial distinction to know what position I need to be in). And then, another one for Doom Spike and Sonic Thrust. Now especially since the melee circle AoE has been removed, there's no real reason to choose one AoE over the other.