SF General has more volume in terms of trauma patients as the City has a larger overall population. Highland has more penetrating trauma (I.e. GSW, stabbings, etc.) though given that Oakland has a lot more violent crime per capita: https://www.sfchronicle.com/bayarea/article/crime-homicides-oakland-17739710.php#:~:text=Oakland recorded 120 homicides in,provided data to The Chronicle.
Lots of surgical residents come to Highland specifically for the trauma experience. Both are relatively high acuity, both are county/safety net hospitals, and both are very challenging places to work for reasons beyond just the patient acuity.