It sounds like you have some depth. I would recommend considering a stack instead of raiding rainbow. For instance, if you’re facing a blue tank, take Gadeirus and Caedmon and leave Boldtusk out.
Also consider varying your team composition depending on who you’re facing. For instance, Caedmon, Sonya, and Seshat all dispel. Taking all three may be unnecessary.
Finally, I’ll vote for Grimm, since you don’t have a defense debuff hero in your lineup. But I also use Triton a lot, and he helps with partial healers like Gadeirus, Boldtusk, or Kiril.