Mexican cartel’s extreme violence is in Mexico, not in the US. I can’t imagine them getting involved with everyday gang politics and other beefs in the US. I’m no expert on all the details of operation, just going by what I’ve seen. I know that they do have influence over piasas that work for them, especially those that have a lot of family in Mexico. They rarely do much violence across the border but will threaten to harm friends and family still living in Mexico if you disobey orders or piss them off.