Tactics for Conflux.

To be honest, I've kind of forgotten about morale. But if we're talking about it, without Haste, it might not work, but with Haste, it's quite easy. We gather all the fairies, one by one, in one corner (or in the places we need) and, using magic and psionic creatures along with the fairies (assuming they are upgraded), we try to quickly eliminate the griffon stack. By the way, who said there has to be an upgraded stack?

At the very beginning of the discussion, we were talking about a maximum-sized stack with upgraded units.
Now, let's model the situation:
Round 1: Cast Mass Slow and Ward with the main forces, while the single units distract.
Round 2: Cast Haste on the fairies, and together with the psionic creatures, they move away from the upgraded stack... the single units, if they are still alive, distract again.
Round 3: Cast Haste on the psionic creatures and attack after Ward on the upgraded griffons... in total, almost half are killed - 17 mana for 3 casts.
Round 4: We can't attack; we retreat, otherwise, the remaining griffons will kill a lot of fairies. Only the presence of Lightning, combined with the fairies and psionic creatures, can help to finish off the griffon king, and that's assuming that the griffon stack on the upper left is not near the griffon king, which is likely.
Even with this approach, if the griffons still can't corner the fairies and psionic creatures, it will take at least another 20+ rounds to defeat them in this way, and there won't be enough mana for Lightning or all the Haste spells.