Did you purposely ignore all of the previous times we've been over this or did they all just happen to slip your mind? Jumping to '123 would get boring fast' despite all of the times where many people in the Healer section have said '123 is the most uncreative way to try and solve this, why not try X or Y' is pretty disingenuous. It's like you're trying to frame the topic as very new, so you can ignore all the previous discussion on it and start the debate from a 'blank slate' position
For WHM, as I have said many times (but I guess I'll link to it again while the opportunity presents itself), reduce Dia to 12s duration, add a new Banish GCD skill with 15s CD. That's all I would need for WHM. These two changes alone would result in this being the rotation, and with the other, more healing-side-of-the-kit focused additions that I'd also implement if I were able to design WHM, this would be the use-count for each of the GCDs in the kit. For anyone not familiar with my rambling rants over in Healer-Zone, Blessing Of The Elementals (BOTE) would be a 500p AOE heal that costs gauge built by using GCD heals or damage skills, and Quake Flood and Tornado would replace Glare Banish and Dia for one cast of each (think Fell Cleave turning into Inner Chaos), to function as a damage refund for BOTE in a similar vein to Misery refunding Solace/Rapture's damage costs.
Again, I'm not asking for GNB or BLM, and I don't expect GNB or BLM tier rotations on any of the healers, not even on SGE. I'm asking, on the damage side of things for WHM, for one new button and one DOT duration to be shortened. That is nowhere near even WAR or SMN. It's a false equivalence to try and compare what I am asking for to any other class in the game, because even with the suggestions I ask for, it'd still be 'more simple' than anything else we currently have in the game. Even if we added everything from my WHM ideas, the 'damage side' of things only gains a 60s CD to throw your odd minute Misery into. Beyond that, there's like 3 heal/mitigation buttons, and a whole boatload of 'skill we used to have, but reworked to be lowerlevel version of current kit', like bringing back Divine Seal as a lower version of Temperance.
And finally, I have said many times that SE can make the potency difference between the filler spell (Glare) and the 'extra complexity' skills (Banish) be lower to punish people less if they 'do the rotation wrong'. As an example, I would make Banish only 40p more than Glare. If someone spams Glare and ignores Banish under my design, they would lose 160p per minute. Half a Glare. Less damage than Crit Variance can steal from you. Trying to assert the 'what if healer does bare minimum' line as a reason to not have any additions to the damage side of the kit is equal parts comical and sad, because the last EX roulette I did on a non-healer, I was PLD and the healer was a SGE who used more E.Diagnosis than Dosis. They put Kardia on me, and then seemed to actively avoid pressing any buttons that would actually trigger Kardia. The run took longer because of that, but that SGE did not get kicked, because none of the other three of us cared enough. We still finished in less than 20mins, so no harm no foul. This 'people will kick because the run is slightly suboptimal', is this a prevalent thing in NA?
edit: Furthermore, under what I would do to WHM, Banish would also be instantcast, so you wouldn't be able to tell someone's not using it unless you have ally spell effects turned on AND you're watching out specifically for it AND you're able to see the difference in VFX between the twinkly lights of Glare and the twinkly lights of Banish. Or you're using a 3rd party tool to check how many casts of each spell are being used. Either way, giving someone hassle for not using their kit as effectively as you expect them to is reportable under the TOS