Sometimes, as in the case of GP, the more they study the worse the result. That's not to say study is not required, but breadth is more what we're looking for -- a little knowledge about many things -- rather than depth, that's what the other subjects are for. Too much depth knowledge and kids try to impress us with everything they've got... and forget that there's a question to answer.
It's like being on a battlefield. The less the ammo, the more care taken to make every shot count (I think Arby came up with this one). The trick here isn't to cut down content knowledge because that is the ammo. Rather, the kids have to be convinced that what they know is never anywhere close to a lot. Then they'll be a bit more circumspect in choosing the appropriate round to hit the right target. I hear Socrates turning in his grave already.
I wonder if it's an Asian thing, this memorize your way into the civil service study strategy? But parents today still think this kind of education is what will bring their kids eventual success. It seemed like news to them when we recommended a more inquiring, evaluative study approach over wholesale absorbtion. They got it when we explained it to them, hope their kids did too.