By the way, artifacts will also be placed on golems.

That's not a given. After all, you have to return to the city to upgrade them, and then go back.

If the opponent attacks with high-initiative troops first, the stone will revive all the golems, and some of them will survive until their turn. If they are weakened, it will be worse for them.

Golems will be eliminated in stacks, and the dead ones won't be resurrected. So, "all alive and well" doesn't work.

And if the heroine is a specialist in fast spellcasting (like Orah, I think), at level 20, she will have very high initiative after casting.

Yes, but her initiative is not 10, but 11. Her advantage is not in the speed of casting, but in the fact that she goes before the enemy hero, which can be important.

2. But after the hero's turn, they will be back in full force.

They will eliminate at least 3-4 stacks. Situation: an elf with tactics and a speed aura (or boots). Before the mage or golems go, the following go:
nymphs (-2 stacks), dancing winds (-1), forest archers (-1), dragons (-1-2, and if they are alt-dragons, then even more). At least 5 stacks are lost, and in general, 1 morale and the loss of the main hero, and the mage hasn't even cast a spell. It's better not to engage in a battle to the Last without preparation.

It's not that unrealistic. At level 20, with the help of artifacts, it's not that difficult for an academic to have 20 SP. So, with a Phoenix cloak, it's about 3000 HP, without it - about 2000 HP. Of course, you need to find/buy the cloak. So, you are right - let's take 2000 HP of damage from the stone as the base.

Okay, let's clarify right away. With 20 SP and a cloak (which, by the way, is quite rare), the base damage is 945 with a cast from an expert, and there may not be a second one (most likely, there won't be). We won't go into the central square, there's another 420 damage there. Pyrokinesis, if it happens, won't be able to deal much damage either, but the Fire Lord will remove half of the golems' defense, and then they're definitely done for. Where did you get 2000 and 3000 from?
And also, if you sense that they will use Armageddon, you can take a perk from the Light faction that reduces fire damage by 2 times.

P.S. The presence/absence of shackles can be easily checked with an auxiliary hero.

If you attack the main hero on the same day, which is not always feasible.

Thanks for the idea with Razazak, I'll test it at my leisure.

You're welcome. This idea occurred to many on the very first day after buying the add-on. It's just that there was information before that Armageddon would hit alt-golems, and then this happened. But personally, I think that in 3.1, at least 3 things need to be adjusted:
1. Orcish Rage, so that, while absorbing damage, it doesn't go into the negative. And also, rebalance it so that, all other things being equal, more rage is spent on this absorption, about one and a half times more.
2. Something needs to be done about the stalkers' invisibility. It's too much for level 1.
3. Armageddon should hit golems, because even the stone in the center heals them with PHYSICAL damage.