Justice is a fan-made global mod.

Added 34 minutes ago

Specifically, PCs can be Tier 6. And specifically, human Knights are too simplistic for Tier 6. In Warhammer, 1 dragon costs as much as dozens of Knights, but here they are simply placed on adjacent tiers. Considering that a dragon eats horses for dinner, and here they took a large horse, put it in armor, put a little man with a spear on it, and voila - a couple of these guys are already a threat to a dragon.

A large horse and a small dragon. Therefore, the problem is probably not with the Knights, but rather with the dragons, which were simply HUMILIATED in size in the fifth game. Even ten peasants with pitchforks can take down such a dragon. And their wives will gladly make dinner out of it in the evening.
In the second game, dragons (and their younger brothers) looked like real flying MONSTERS, and their roar was terrifying. It was clear that we were facing the KING of the heroes' bestiary. Although even there, it could have been made even better...

Of course, they break the balance - that's why Knights don't belong on Tier 6. Although, again, with a stretch, if you weaken them and increase the growth rate from 2 to 4, you could leave them, but why - when there is such a magnificent monster as a Griffin for Tier 6.
Moreover, if I'm not mistaken, Griffins also enjoy eating horses, and if you add a Knight to the mix, the very same one who was plowing the land yesterday...

Yes, but I, for example, was still glad that in the fifth game, Griffins were given the respect they deserved, and they were placed at least on Tier 4, the growth rate of 5 is not so critical, unlike what we saw in the universally beloved third game, where with an additional building and a castle, there were 17 of them or so, and that no longer smelled of dragon scales, it is much more likely that they were in Erathia instead of ordinary fighting - DOGS, it just looked more beautiful and mythological. And even in the quite reasonable second game, they were still nobody. I think the point here is that the developers of Heroes imply that a Griffin is at most the size of a lion (well, about 70-80% of its body is a lion). With the head and wings of a very large eagle, so it is still very far from a dragon.
The idea of weakening the Knights and increasing their numbers is good, but then you would have to change all the other tiers in the same way.