For what it's worth, the dread necromancer is tier 3 and I think it is an excellent model for a minion-themed PC. It's not the horde that makes a necromancer wizard T1. A dread necro does get powerful minions with special abilities (if nothing else, Create Undead for bone/corpse creatures), but they're relatively limited by his rebuking compared to the vast hordes of skeleton and zombie chaff.
(This does become broken if dread necros try to do the ridiculous trap room/Planar Binding/Corpse Efreet business - which is why I tried to specifically counter that kind of nonsense in my proposal for greater YMZs.)
Edit:
An extra save every d8 rounds is a very long time being helpless for an at-will ability that becomes twice per round rather early on, and is very likely to be enough for the YMC to finish eating the brains before the target gets another save. By comparison, a mind flayer needs to pass a minimum of two grapple checks to eat a brain, almost certainly at least three, and quite possibly more, while the musk puff -> mind eater combination is essentially a guaranteed kill once the initial save is failed.