One of the few certainties in this Pac-12 football season — in any Pac-12 football season — is the impact made by newcomers.The newbies could be players, either transfers or freshmen.They could be assistants, coordinators or strength coaches.They could even be conference executives.The best recent example is former Washington State quarterback Gardner Minshew, who arrived in the spring of 2018 and became a sensation several months later.Last year’s collection didn’t have a newcomer of such singular impact but, rather, an array of influential players and coaches, including Oregon defensive coor…