Which units would you like to replace/add?

Nope! Peasants bring in the money. I managed to accumulate almost 1000 from dwellings, and now I get 1000 gold per day.
Golems are great fighters (especially for Razazak). I teleported them into the enemy camp, gave them stone skin, and that's it.

Added 4 minutes later
I would remove the zombies and add dead knights, but not the ones on horses, but the foot soldiers in armor with shields.

In my opinion, peasants are only good because they provide 20 extra archers per week... It's a pain to accumulate money from them, although it's at least something.
You definitely shouldn't remove zombies from the Necropolis! It's a classic! And knights on the second level??? Are you kidding me???
P.S. Doesn't anyone think that zombies are just peasants who died of binge drinking?:D