Markel and Sandro, which of them is more effective as a Necromancer?

Setting a Necromancer as a benchmark, especially one who is only rarely mentioned in the game, means inventing traits for him that he may not even possess. Or are you referring to Sandro from the old universe?
And why are there so few answer options? Perhaps Arantir is my benchmark? Or Naadir? Or maybe I consider them all evil creatures who don't deserve any kind of poll?