i grew up playing baseball. i never had a problem until i was a senior in high school. i was 17, and had one of the better arms on a bad team, so i was put in positions that varied between games including third base, left field and shortstop. i threw my arm out, to this day my shoulder isn't right.
my point is, that reps for dungey, as long as they are reps, are good. if he is overthrowing than that is bad. if his arm is "tired" and that's it, the staff should be able to manage it. if they are pressing him to make throws he cant make and hurting his arm, than that is bad. but there is no way to know which one it is without ED being honest about it. i would have never told my coaches that my arm hurt. my guess is that it is fatigue from reps but as far as i am concerned the only way to get through that is more reps.