Brian the amount of calls you wanna buy is tied to the fact you cut your NET delta. That means that right now (29th nov, SPX trading at 2208) if you have 1 condor, you gonna have a net delta of 3.9, if you have 10 condor you are gonna have a net delta of 39, if you have 15 condor you gonna have a net delta of 58.5 and so on.
So the amount of calls you need to buy is tied to your net delta, which is tied to the amount of IC you have.