Let’s come up with new “war machines.”

Then, the undead should also have a similar wagon that would reduce morale... And if it really doesn't work out to create new machines, then at least add new skills for them for each race, plus a unique appearance, plus differences in the characteristics of combat machines for each race; for example, dwarves could have ballistas with a large amount of health, while siege engines, on the contrary, would be the weakest, and so on.