Food for thought:
If you walk in to a Bass Pro, Cabela's, or other outdoor store, and walk over to the bows, you'll most likely see a sign "NO DRY FIRING". Dry firing a bow is pulling back the string and releasing without an arrow on the bow. Dry firing puts too much stress on the limbs of the bow and often damages the bow, hence the warnings about no dry firing. When a bow is fired normally, with an arrow nocked, the arrow absorbs that excess stress, preventing damage to the limbs.
You can probably see where I'm going with this. Liken the bow to an arm, the arrow to a football or weighted ball, and dry firing to throwing with the 5 oz. ball as opposed to a "loaded" arm with a heavier object, and make your own deductions.
Not exactly scientific and data driven, so take it with a grain of salt.
I'm a personal believer in long toss and don't really push for weighted ball programs, but I don't have a problem with weighted baseball programs. FWIW, as a teenager I cut a slit in a tennis ball, stuffed a bunch of pennies in it, and played catch with it to get stronger.