haha broscience, nice. I feel ya on that... it's not all about the weight.
Power Vs. Strength; think of it this way, strength as we are talking about here is slow strength; it's all about work, force times distance. With power, you add in a speed component. For instance, to build good shoulder strength you would want to do things like military press, forward/lateral deltoid raises, shrugs... things like that. For power, you want some external resistance (weights, weighted vest) but there is a speed component. It's kind of like plyometrics, but plyos aren't only for lower body. I do plyometric pull ups, which are great.
My favorite disc golf exercises are medicine ball power exercises. Medicine ball slams, which require a 2-5 kg (2.2 lbs per kilo), are great for developing powerful shoulders. All you do is take the medicine ball in both hands(not too heavy, as the speed at which you release the ball is more important in these), hold it just behind your head, and using your abs and arms/shoulders throw it into the ground just like throwing a tom/thumber. Make sure your arms follow through, as stopping them before can cause injury to your rotator cuff. Rotational medicine ball throws are also awesome. This requires a slightly heavier medicine ball (6-8 kg). Get into an athletic stance with your left hip towards a concrete wall (do not do on drywall or any surface that isn't solid, you will break through the wall!) Athletic stance is definsive stance, Knees slightly bent back straight. Hold the ball in your right pocket (not actual pocket, just area) with your left hand on the bottom of the ball and your right on the top of the ball. Keep the ball on this plane as you throw it, the momentum starts at your back leg (right), rotate at the pelvis and shoulders and throw that SOB as hard as you can while staying low. Your back leg will come off of the floor after it leaves your hand for the same reason that following through as mentioned above. Repeat on the opposite side. 4 sets of 6-8 reps should be good for both.
Another thing to consider that I think is really important is when doing strength building exercises to not forget about the eccentric portion (when you are lowering the weight in bench/ bicep curl / military press. Make sure it's nice and slow, this helps so much with deceleration, which is the number 1 cause of injuries in throwing sports.
Athletes Train Movements, Not Muscles; you have to carry the engine.