Gremlins

If you rely on Gremlins, they need Battle Frenzy, and you need to acquire two artifacts: the Necklace of Bloodclaw and the Unicorn Bow. Then they will shoot quite well, so I disagree that they shoot poorly. I have two replays of battles where they eliminate any stack of Orcs in one turn. For example, 450 Centaurs were taken down by their shots in the first turn. In that battle, both the Orc and I were level 29. The artifacts gave them attack, health, and initiative. I practically defeated the Orc without any losses. As for the first-level units, I think Orcish Shamans are the most useful in battle, but not Trappers, but Shamans, because they block any spells.
Anyone who doesn't believe in the power of Gremlins can watch the replay of the battle after which all questions will disappear, and this is without Battle Frenzy, as there was no mentor anywhere on the map, only the Unicorn Bow and the Necklace of Bloodclaw.