Heroes 5.5 WarGame Edition - Tactical Edition.

Isn't this the reason why the game developers gave different bonuses to the "attack" (5%, 10%, 15%) and "defense" (10%, 20%, 30%) skills, and perhaps it wouldn't be worth making them the same here (in both cases 10%, 20%, 30%)

Hello, with attack and defense parameters, only their absolute difference matters, not the percentage.

Also, I think it's because in the vanilla game, the focus tactic works: whoever attacks first in a battle has the advantage (many attacking units and archers). Defense is less advantageous, so the developers gave a smaller percentage for improving attack.

Nargott in his mod increased the role of defensive units and tactics: less movement, Heavy class, improved "Defense." That's why the percentage increase in attack and defense parameters is the same in this mod.