Which sorcerers to lead rubrics?

Pretty explanatory, but just wondering which sorcerers people use with their Rubrics? I see lots of people using the Infernal Master and I think I must be missing something? I tend to have Ahriman, leading a squad of flamer rubrics, and then rely on exalted sorcerers because of the 4+ inv they grant gives us a little bit more survivability if the other units ?

What do the rest of us do? What are the benefits of the others?