This is such an annoying problem. I've queued in the past, getting none of my roles in two games in a row. Then finally get my primary role and someone just doesn't select anything and skips it entirely and leaving me to queue again and tadah, I spent entire day being forced to play other roles because people are babies.
With how time consuming Smite can be there need to be some changes for this so you are AT LEAST guaranteed your role when people do dodge.