Question: is vasto lorde stronger than espada?
Answer: Reputation: Arrancar Vasto Lordes would be stronger than most of the current Espada and occupy the top few ranks (if indeed Aizen already has some), and Aizen hopes to eventually have an Espada roster consisting entirely of VLs. Non-arrancar VLs would probably be around mid-Espada level (very strong arrancar Adjuchas).