Wow...I have entertained this scenario many times...I honestly could not kill unless in self defense or to protect the defenseless. And that is the premise of joining the Zs to kill upon order. However, one never knows the strength of self preservation until faced with such a choice, right?
One of the survivors of the 72 (which now reports say 77) stated that in Veracruz at a Z safe house those who could not pay demands were offered another choice...to join them and the first act was to torture and kill some of the very persons that were traveling with them on their journey. Think about that. I am certain I would take a bullet, but one can never be 100% sure.
Yikes! How old are you Kyle? 12? I don't think they just politely offer. More like force and coerce under threat of death to you AND your family. Your post sounds like some kid getting a shiver from a ghost story, instead of the gawdawful violence, corruption and slaughter of innocents that has been the norm in Mexico now for far too long.