The Create Greater Undead feat that you get from ESF:Necromancy animates dead at a lesser Undead Caster Level than the normal Create Greater Undead in your spellbook. Unsure if it's the same for other classes than the one I list.
Steps:
Create Wizard
Level to 21
Take ESF:Necromancy and Create Greater Undead
Use both
The Feat version will animate Tier 3 undead, the spellbook version will animated tier 5.