Humans vs. Mages

Miv easily solves the problem of the mages' excessive initiative.

In reality, Miv will need to manage to cast his General speed buff before the Haven troops can do anything. Besides, if the speed buff is cast first, we won't have the opportunity to defend against the inevitable casting of the subjugation spell on the Knights, which is even worse. So, I think that the best solution here would be to have the maximum number of artifacts on initiative (which is not always possible, as the mage can easily increase initiative with minor artifacts), and the Staff of the Underworld.

Added 3 minutes later

By the way, regarding the Guardian Angel ability – I think it's a completely useless skill, just like the Humans' special ability...

Actually, the Guardian Angel can still be useful in a rush, but in the late game, it's probably really useless, although there were cases, for example, when I was playing as Necromancer against Haven and only one stack of zombies remained, the special ability and the Guardian Angel would definitely have been useful.