My opinions with nothing to back them up:
A lot of the potential for power we have is the fast twitch abilitly we are born with. Since most of us never use all of our natural potential for speed and power due to improper mechanics often players with less natural ability but better training techniques can eliminate that power leakage and end up more powerful.
Players in any sport I've been around that are allowed (or forced) to use maximum power at an early age almost always carry it with them as they get older. That kid that is playing on the men's slow pitch softball team when he's in the fourth grade, or that kid that's on the high school golf team when he's in elementary school, or that kid that gets moved up from Little League to Pony League and is forced into using maximum power to be able to compete will usually always be a power player for life, and the kids that didn't will have to try to catch them in the power department through training and mechanical improvement.
Most golfers that have power that didn't take up golf as a kid carried the power they learned from baseball, hockey, or swinging a sledge hammer or a ax on their dad's farm with them into golf. Then the only thing they have to do is pull off the changes in mechanics, mostly getting over the back palm up/front palm down at impact that baseball and swinging a hammer or an ax require. (Easy to say, much harder to do).
Let's say I'm a college baseball coach and you let me watch two kids at 12 years old pitch and one of them is as wild as a March rabbit but throws everything as hard as he can and the other has good control but never turns loose the fastball, and then I never get to see those kids again. When they get to college age I have to pick the one I want on my team without seeing them. I'll take the wild kid that pushed for power. More than likely he will have learned control and more than likely the other kid will have not have the power to get a fastball past a college hitter. He may be a Greg Maddux or a John Tudor, and may be the best pitcher of the two, but without knowing for sure I'll take my chances with the power kid.