I've been working with one of my clients on improving his proportion and symmetry, as he's all upper body and absolutely no legs. I tried explaining the traditional measurement of symmetry - upper arms, neck, and calves all the same measurement. He asked me if there was a standard like that in terms of strength, particularly with powerlifting exercies (he recently started squatting and deadlifting), and I didn't have an answer.
For example, if I'm 200 lbs and can bench press 350, how much should I be able to squat and deadlift to be "proportional" in my strength? (I'm not, and I can't, hence the "for example" qualifier)