Orcs vs. Humans

Even with Keen Mind, a hero won't be able to cast spells before the Cyclops' first turn. The hero's initiative is 10 and doesn't change. Keen Mind will move the hero 25% along the turn order scale. The initiative of Daughters of Earth and War Chiefs upon entering battle at level 1 of Fury is 16 and 15, respectively, without artifacts. Artifacts can further increase it. The screenshots of the start of the battle (which I posted earlier) show the order in which the Orc units and the enemy hero with Keen Mind take their turns. Out of 10 attempts, the hero with Keen Mind only overtook 1 War Chief on the turn order scale 2 times. Remember, this is without initiative artifacts. In addition to rings that provide +10% and +20% to initiative, War Chiefs can also be sped up with dragon artifacts, both as melee units (+10%) and as "small" units (+5%). Shamans can be sped up as melee units (+10%), as casters (+10%), and as "small" units (+5%). This scheme does not include flying units (whose initiative can be reduced with Storm Wind) or ranged units (whose initiative can be reduced with Misty Veil). That is, to reduce our initiative, the enemy will have to find the Relic Staff of the Underworld.
After entering the battle, the Daughters cast Haste on the War Chiefs, and their initiative becomes even higher.
Each turn of the War Chiefs moves the Cyclops along the turn order scale. 3 stacks of War Chiefs with 50-60 units in each stack guarantee 2 and possibly 3 turns for the Cyclops before the hero with Keen Mind.
It looks something like this:
A stack of War Chiefs moves the Cyclops 60% along the turn order scale (60 is the maximum possible shift), meaning the Cyclops go immediately. If the Cyclops' morale doesn't trigger, they move to position 0 on the scale and need 2 "pushes" from the War Chiefs to move to position 1 and attack. If morale does trigger, they go to position 0.5 and after one "push" they attack again. If morale triggers again, the third attack of the Cyclops will again be possible after one "push". Thus, 3 attacks by the Cyclops are possible before the hero with Keen Mind.
And let's not forget about War Cry. At level 30, it will move units 70% along the ATB scale, and our hero may go earlier with the same Keen Mind and/or Empathy/Knight set, which will be effective with the high initiative of our units (units go more often => morale triggers more often => the hero moves along the scale more effectively => more often moves the Cyclops).