We recently considered the idea of goblins riding werewolves (the base could be taken from bears or wolves). I think it would be worth replacing centaurs with them. I really only saw the combination of orcs and centaurs in this game. And if you remember the legends, where centaurs are mentioned, orcs are not even heard of, and vice versa. Instead of shooting, goblin riders could have a charge-and-retreat attack + cowardice. This would correspond to their nature. And to compensate for the lack of archers, the first upgrade for level 1 goblins could be made into archers. The animation could be taken from goblins on the city towers, throwing stones or something, they throw something there. In fact, the model of the thrower exists in NCF. It turns out to be approximately the same as with the Necromancer. The first alt is a melee fighter, the second is an archer. Well, I have a third, a mage-archer. Goblins already have a mage (shaman). In my opinion, it would be quite logical.
In general, in my opinion, not every change leads to an improvement; you need to weigh all the "pros" and "cons".