What can i tell you? Aeron only good thing is the aliment protection (3 turns) and the stats. Otherwise is outmached by c.rigard in all aspects(healing, cleanse to all and atk boost to all not matter the colour).
You already have Kunchen so you have filled the 5☆ healing purple role.
You have covered the dispel too with seshat. Domitia could serve you well in wars as a second dispeler , in a second war team maybe.
Do you have c.rigard? If so, have you emblemed him?
From those who i wouldnt give tabards is Obakan. I have face him in many defenses and hes not useful at all.
The last one is Quintus. Do you have emblems to use on him? You can pair him with c.tiburtus and c.rigard and build something. It wont be gamechanger but will add diversity.
So , personally i would go Domitia》Quintus》Aeron》Obakan.
This because i have already two c.rigard maxed and a third one in coming. So i see aeron less useful to my roster needs