Well I offer there is comes consideration of how one builds muscles and what kind they are. You could have someone built like Arnold Schwarzenegger once was but not be as strong as someone like Pat Davidson perhaps.
Well yes. Extreme bodybuilders, the ones with the really bulgy muscles, are often weaker than simple athletes with a fraction of the muscle mass. My arms are a little on the bulgy side as well, but I find myself evenly matched in upper torso strength with this one guy who looks almost malnourished. Size is a poor indicator in this regard.