There are 3 perks that are supposed to affect ONLY the undead and atronachs.

One allows you to summon two undead or atronachs
the others allow you to summon undead and atronachs twice as long and twice as far away.

Yet all of these apply to the already OP dremora lord spell which makes me dissapointed given they also give a power up atronach

Heck even 2 supercharged storm atronachs are nothing to a single dremora lord.

Because the Storm Atronachs have a ranged attack. The Dremora Lord is a pure melee fighter.

The melee v. ranged balance of that sort is not unheard of.