UNIT - Creature Balance + Visual Changes

Shamans, although they are women with knives, are elders, much smarter and wiser than their fellow tribesmen, and besides, they possess extraordinary magical power; I think relegating them to Tier 3 is a clear insult to them.

Mental strength is not needed in a fight; otherwise, boxing weight categories would be divided by IQ level. An Orc is simply twice as heavy as a female Orc; it would be a disgrace for him to be weaker. But he is indeed weaker as a fighter (even if you take away all the buffs and debuffs from the shamans). By the way, the shamans look rather young for elders; do Orcs know a thing or two about cosmetics?
Although, the issue is not so much with them, but with the fact that the Kents feel out of place even on Tier 3. However, moving them to Tier 3 is already a step in the right direction.
In short, I will not insist on moving the Kents to Tier 4, as I understand that this is less conservative and would affect more units than I would like.

Bears are, of course, more powerful than Knight horses, but horses are just a means of transportation for the Knights...

Horses are a means of transportation for some light cavalry, but for Knights, horses are the main striking force and power that overpowers and tramples the enemy.
Again, this does not mean that Tier 6 Humans should necessarily be weakened and increased in number, but I would do so; the Knights are too over-buffed, both in relation to Dragons and in relation to other cavalry/infantry.
However, from the point of view of training mechanics, weakening the Monks to Tier 4 also means weakening the training of Monks and strengthening the training of Knights; against this background, I would say that increasing the growth rate (with an individual weakening of one creature) for the Knights is highly desirable.