Which Orc hero do you prefer?

So, for Tilsek, it's more beneficial to frequently reinforce the Orcish fighters than to also use executioners. Therefore, I agree that Tilsek is better.

He also stands out with his ballista. If there's a chance to upgrade the ballista (and there are many chances), it will crush even large armies of neutral creatures.

Which Barbarian heroes do I prefer?
Kragg: because his hero attacks are very powerful; if you get the "Empathy" and "Devil's Strike" skills, he can kill several slow level 7 creatures with his average army.
Argat: because of his high movement speed on the strategic map. He can be chosen for large maps.
Haggesh: a lot of centaurs. And centaurs are excellent archers for the Stronghold. Besides, she initially has the "Memory of Our Blood" skill, which is vital for Orcs.