Necromancer tactics against Conflux.

But what about the shield? It's meant to protect against ranged attacks...
The key magic is slowing.

Shields come in different types... :)
There's also one that helps in melee combat (earth).
And slowing isn't critical – anyway, more than two stacks of griffins can't fight vampires at the same time (in the corner of the field). But I also agree that 12 vampires won't stand against two hundred griffins without a hero with at least 10/10 stats. And that's very doubtful in the second week...