At the youth level a lot of issues with hitters are mental issues. When facing faster pitching many young hitters begin wondering/doubting if they can even hit it. That uneasy feeling in the box leads to broken down mechanics and if the mechanics aren't very good to begin with the hitter is in a lot of trouble.
There are "quick fix" things that can be done to help a hitter succeed (i.e. hands back). In the "instruction" world that is probably the best approach to take. You want a kid to succeed and the sooner the better. But in the "real" world, where parents like myself work with their own children, developing the potential to its fullest is the goal. Short term results vs development (long term results).
In my opinion young hitters just don't know how to rotate efficiently. That won't change regardless of where they start their hands or if they get their front foot down on time. That is where I'd start, but I'm not a instructor.
Jason