I see this all the time in the 12-year old baseball team I help coach. There are a few kids who have "strong arms" but they have terrible technique. They don't get their legs into their throw or throw the ball sidearm which creates bad spin on the ball or other things with bad technique. This poor technique causes inconsistency and inaccuracy. When my son was young, I taught him the proper grip and proper throwing motion to get a consistent back-spin on his baseball throws. Even though he doesn't have a strong arm, he's extremely accurate with his throws. I will try to work with the kids or talk to their parents about techniques to improve how they throw the ball, but they don't want to listen. These kids are only 12, I couldn't imagine trying to overhaul a high-school or college aged kid.