Who said anything about combos? That is your inference not mine. Even if they were to do combos, Dancer's aren't interrupted should they press their procs. They could easily design them around proc based gameplay not unlike Sage's Toxicon system but more refined. QooEr brings up the better argument though. Scholar used to have five buttons to achieve its DPS and not a single one of them interrupted their healing. Ironically, they actually healed more back then compared to nowadays because we lacked the sheer number of overpowered oGCDs. I'd also like to point out Heavensward and Stormblood debuted the hardest content this game has ever seen and yet none of the healers struggled to perform their base role (healing) yet apparently reintroducing those same abilities will cause wanton panic and break all the healer balance.
What absolute nonsense.
They could quite literally take the potency of Glare III, cut it down by half and give us another DoT to manage instead and that alone would be better. Not by a lot but certainly better than what it is now.
Since you asked, I'll use the most button bloated healer, Astro, for my example.
- Play merged into Draw (Which should have been the case already)
- Crown Play/Minor Arcana removed entirely
- Benefic upgrades into Benefic II
Doing that alone cleans up a lot of buttons. I'd opt to scrap Minor Arcana because in its present state, it's either a DPS button or a FeelsBadMan because you never need Lady. So we may as well use that button space to give back some actual consistent DPS alternative to Malefic spam. From there, I would borrow Sage's Eukrasia system and give a form of it to each healer with the goal being to shore up hotbar space. That way you could combined Helios and Aspected Helios into a single button, with either being accessible through Astro's version of "Eukrasia". You could do the same with both Celestial abilities.
You could drop Horoscope and bake the potency into the aforementioned GCD heals, same with Synastry, which almost never sees any use. There's also an argument to be made healers have too many oGCD heals. Hence why they have so little to heal. So that's another option to explore. Finally, you could overhaul Astrodyne into a DPS tool for the Astro themselves—especially when playing for three seals offers such negligible gains that even top tier Astro just settle with two. To compensate though, return Divination back to what it was since a random self buff that you press and forget isn't all that interesting on a healer to begin with.
And all this is just off the top of my head. Is it all perfect? Hardly. However, it's a start to both clean up button space and pave the way for interesting gameplay because pressing Fall Malefic 150 times certainly isn't.