[Excedrin]

Lvl 38 Necro, IMO, the grafts are dropping at a steady pace, sometimes too often.

I recieve grafts quite frequently, perhaps 1 every 3-5 hours in game (can't say how many corpses since i don't count).

Keep working it, it get's better as you level.

Also, you can always purchase them from the broker. There are lots for sale, cheap.