There's nothing stopping anyone from clearing savage as a Summoner other than themselves. In any case, that's more due to damage than anything else. Buff the numbers and suddenly you'll see all these high skilled raiders switch to Summoner. As for outside of savage? Summoner is about as common around here as Reaper. Double Reaper and double Summoner is an extremely common finding in trial/raid/alliance roulette. If savage raiders are upset that doesn't mean a job is unsuccessful or dead.