Write how you imagine it – level by level... RomaShSh's idea with hero names won't work...
Actually, I would also be very happy with such an addition.

We can sort out the monsters. It's simpler here.
I'm not very familiar with the details, but in the case of heroes, it's really difficult to prove who is stronger. Therefore, I see two possible solutions:
1) Why not make it a random choice? And no one will be offended :)
2) If we are going to make a distinction, it is only possible at the initial stage (at the first level, when the hero has just come from the tavern). And this can only be done by differentiating the initial spells.
For example, Order. Theodore – Mirage (50% ranged protection and hides the location of the selected target). Corvus – Accuracy (increases the damage dealt by the selected unit by 25%, removing penalties for shooting at long range, through walls, and obstacles). Silan Zanj – Magic Fist (the selected target takes damage, the amount of which depends on the mage's level – at the first level, 22 units). And so on.

Thus, we need to evaluate the spells by their strength, and then the hero accordingly.
In my opinion, Magic Fist is stronger.
But there is another problem. How do we evaluate Tactics, Scouting, Combat, and Nobility? Another dead end. I suggest random selection :) :) :)

Respond….