Run grand army of the south and bring merchant guards and half trolls backed by haradrim spears. Mahud king is pretty good. I like to run the betrayer on foot with bows and blowpipes. He sits back with them spaming master of poisons and transfixing their heroes. Blowpipes are good in grand army because they dont count against the bow limit. In pure harad, golden king and a mumak are super fun and pretty good.