company of heroes

[militarist]

it looks like the 2 main differences between hellbind and seduce - when you seduce you also have to go through moral check, and the second one - succubus has seduction 11(if wiki is right), which is better then usual spellcasting 10 check,but still doesn't compensate moral check.
As for amount of hellbinds with no penetration items, very simplified mathematics is 3-4 casts for MR 12 targets, 6 for MR 15 targets and 10 for MR 16 targets.