Mmm, and ideally such a thing would be possible here. Unfortunately, however, we have a raiding paradigm wherein certain attacks from the enemy simply cannot be 'healed' through. They do more than 100% of our Max HP, and serve to 'require' mitigation to survive. With that in mind, the 'sliding scale design' would mean that, in a WHM/AST comp, rather than the current situation of 'it doesn't work', I'd have it so AST is given ways to be the 'Mitigator' (eg by bringing back Nocturnal Sect, which reduces throughput of skills like Earthly Star but attaches Mitigation effects to them), but has little to no access to Barriers. On the flip side, I'd make WHM have access to Barriers (as a Lily spender), but little to no access to Mitigation (outside of Temperance). Thus, the two would need to work together, and cover each other's 'blindspots' if paired together. Similarly, SGE would take the lead on 'Pure healing' in a SCH/SGE comp. This hypothetical '5th healer' that is equal Pure/Barrier, would be flexible and adapt to their partner on a fight-by-fight basis, focusing more Pure healing output when with a SCH/SGE, and more on Mitigation when with a WHM/AST
An entirely HOT focused (eg what I suggested, but it doesn't have the mitigative half of the gameplay) job sounds cool on paper, and it can be in other games (where damage is faster paced, multiple hits, and doesn't instantly take us from 100% to -20%), but here it'd mean another 2 nonfunctional comps in raiding (WHM/new, and AST/new, to go with our current WHM/AST), and I'd rather reduce the number, not increase it
