Since there are debuffers like sand out there (all those Zimis, Celis, Sonyas, Caeds, Sabinas), reposters on defense won’t be a good choice for defense.
But both title heroes shine stacked to attack whatever. They will be devastating especially when combined with dmg deviders against AoE.
There’s not much of a difference between them. Take who ever you want or the matching color.
Momentarily I’m running like hell through S2 hard with a purple stack of Aeron, Cyprian and Proteus and my two green mean mamas. Currently 18/10 without any retries using 3 to 5 mionor items per lvl.
I make the bosses commit suicide with Cyprian, prevent them from charging with Proteus and renew my meatshield with the other 3. Real fun.