Heroes 5.5 WarGame Edition - Tactical Edition.

We've already tried using Teleport on all targets, and it wasn't very effective – it's an ultimate spell for pulling out vulnerable ranged units and immediately destroying the enemy army.

That's what I'm saying – if the opponent is clearly playing a defensive game with closed-in ranged positions, then Teleport on all targets simply breaks their entire tactic, which isn't ideal.

It was rarely used on our own troops in that case.

Probably only with Surprise Attack.

Vampirism – you can enable the option to cast it on the enemy as well, but what's the point? To break morale and retribution? Oh, I get it – to break control.

You can break morale, resurrection (as a spell and from Archangels), prayers, empathy, retribution... There are many things you can break with Vampirism. You can slow down high-initiative ranged units in a defensive formation, which you can't immediately reach with Vampirism.
There was also the idea of making Raise Dead affect all targets – instantly reducing the stack's HP by 20%. :D

Yes, I think we should push for a release with an approximate balance, because all the abilities have been distributed qualitatively for a long time. Precise calculations may take time, while there is an interest in trying it out immediately.

I'd be happy to try it.