The Lords would be the general units. I don't really see them as a 'unit' in their own right, since they would be far too few in number to actually form up a large unit. It would also be the only way we can have a unque model for the Vampire leaders. to show up against the rank and file.

As far as the magic goes, I am also nervous about making units of magic throwing warriors. There is a minimum unit size, and this would be a problem. There would be a handful of Necromancers at most in a an army...more would look wrong. If I can find a way to mess about with things to get around this, then I will.

I managed to fool RTW into letting me use a human skeleton in an elephant unit ( with invisible riders due to the lack of a saddle bone ) and this worked well for me. It greatly reduced the size of the unit. There were some issues...and I could not make the archers on the back fire ... but it's an avenue I can explore for magic firing units.

Having a massed rank of these is out though... just looks silly and unrealistic.