I think if you fixed healers but tanks still played as they are they'd still play way too similarly to each other, and not just with how they deal damage, but how they execute their role itself. It's a problem that the healer role shares.
I actually legit miss things like using Leeches for Berserk, waiting to activate Veil to when I need it, waiting til Blood Price is done to commence Holy stun spam (or the reverse) and considering how best to heal Living Dead (to an extent) BECAUSE there was variety in that stuff that made the roles feel different to play with different groups.
I'm not saying a return of the annoyances is the goal, just that sometimes the annoyances occur because of differences and they're worth putting up with to keep the diversity.