Uninvited guests.

I watched how the archers behave under Rupert's command. It's very peculiar; I can't say I liked it. At the beginning of the battle, they always end up at the very end of the initiative order, with an initiative of 18, they move after Hydras or Zombies. In the next round, the archers enter machine-gun mode. 4 stacks of demonic horses against one stack of Rupert's red archers could only make one move.
The fact that the archers fall behind at the start negatively affects skirmishes with other archers or mages: the opponent kills them as much as possible in the first round. In battles with heroes, there's nothing good about it – they are targeted, and the entire enemy army casts spells on them; then, with the remnants, you can try to strike back. The "berserk" placed on the first turn cannot be removed, and on the second turn, no one can intercept the archers.

Good point about the archers' setback on the ATB scale, but, to be fair, it should be noted that the archers' initiative of 8 already makes them very slow compared to most other units, including other archers. Even if you equip them with artifacts that increase initiative, some elven archers will still move faster, and the enemy hero will too. Taking damage before the archers' turn is a normal occurrence for humans, but there are ways to minimize this effect. The most obvious is a tent, dividing the archers into 2 stacks. You can also give the hero evasion, antimagic, resurrect them, cast a mass dispel, and so on. With a sharp mind, you can do this before the main enemy stacks move.*

If this setback is still too critical, I will make changes to the special ability (make the setback zero or trigger the charge not at the beginning of the battle, but on the archers' first turn).