Dad definitely gets more play, imo. With all of them, really. Except Jason.
But I feel like that probably hooks in to some psychological thing too. "Mother" is about being a baby, but the boys all lose their dads in that time of life when they've left the nursery and were looking up to their dads as role models.
Obviously I'm not speaking as a psychologist or anything, but I've always felt there was something to that, that for the boys their mothers represented just some perfect love where as their fathers were the parent they were trying to understand and come to terms with as people. Basically, it's like Bambi and his mother. When the time comes for him to be a man, dad takes over.