The most difficult alternative

Griffins have one problem – they are weak in the early game.
There are situations where 1 dragon is stronger than a squad of phoenixes due to its ability to inflict confusion.
Both satyrs and leprechauns are useful; their effectiveness depends on the situation. Luck changes the damage received, while zeal not only boosts morale but also changes the damage dealt.
The green grasshopper can actually counter the griffins, as it doesn't just have a first strike ability. Only water elementals or sprites can handle it if it's unsupported (but I haven't tested this).
Regarding the flash and amplifier combination – it's a good idea, but I haven't encountered such a combination.

There's one problem with this – morale changes during the battle depending on the damage received/dealt.

I already said that someone might disagree :) I'm not saying that I only build these units; it's about prioritizing – when you have multiple cities, you can build dragons in one and take one into your army to inflict confusion.
I don't understand, since when does morale increase damage? It's my opinion that satyrs are unnecessary; you can have your own opinion.
Are you talking about the grasshoppers' entanglement ability? I said that I don't reject them, and like dragons, you can summon them with a hero in certain situations. As for entanglement, I wouldn't say it's dominant – speed + first strike + entanglement makes them attackers who immediately rush to the enemy and are the first to engage.
By the way, this combination should be noted – because 6 mana - 33% - 2 = 2, and 6 - 2 - 33% = 3 – it's unclear how it's calculated, so this combination might give nightmares 3 uses of Terror.