GOs can advance within the Guild, but it is very hard for them to do so. Those especially mean and rugged sometimes become Pest Control Managers. It's a better paid job, but a dirty one if there ever was; it entails dealing - permanently - with various nasty pests, from hostile fauna and flora to mutants. The Pest Control wear light, chem-resistant, flying suits to get where no one else can and are generally much more dangerous (and enthusiastic) than GOs, but their area of expertise isn't dealing with armed and organized opposition - like us.