How to round out a spearhead army to 1500 and 2000pts

My friend has the cursed shacklehorde and added reikenor the grimhailer to create a 1000pt army, he's interested in adding lady olynder but what other units or heroes would fit to get him to 1500 and 2k points? I was thinking of taking lady olynders regiment of renown and reinforcing some units but is there any other reccomendations?