Defensive play can be taught, but I think your underplaying how hard it is to teach. One of the most common reasons offense-inclined prospects don't pan out is you can't teach them defensive play.
And while its harder, goal scoring can be taught too.
And instead of imagining two 50 goal scorers in the lineup or a PP with two snipers and Hutson, I'd rather imagine a team with a bunch of dual threat forwards who can drive play, create chances and score (plus Hutson). I don't actually think goal scoring is the most important skill, its just that goals are the most important thing in the game. Two many guys who score goals and not enough guys who can get them scoring opportunities means you wont ever have 50 goal scorers.