People really overstate the "you can just coach defense" thing. It assumes a lot of things...not the least of which is: "are you telling me not one coach ever has tried to tell him to check?"
It's not some automatic thing, it's not a slider you can set. Not all players have the mental capacity to handle that, not all players develop the determination to check, not all players develop the technique to check, etc.
And there's a lot of different avenues within each of those umbrellas too. Hockey sense isn't a 1 or 0 thing. It's on a spectrum. And within that spectrum there are different things that make it up...anticipation, risk mitigation, pattern recognition, spatial awareness, etc. etc. And depending on where a player's strengths and weaknesses are within those sub-categories will produce certain results.
And similarly, there are different types of defense too...there's mental defense based around anticipation, there's technical defense based around proper technique - usually stick-led these days, there's physical defense, there's effort defense - where a player is working really hard, which can be useful, until he overplays it...etc.
Effort defense is the only one that's probably always there. But it's not the most effective. Look at the DPE 2.0 when we had guys buzzing around at a zillion miles an hour, sliding across the ice with their mouths open blocking shots and what not...they were the 6'5" hookers and holders of 2003. It manifested itself differently because the game changed, but it netted the same result: garbage.
I'm not saying things aren't teachable, I'm not saying that a player at 17 is serving a life sentence on his flaws, but it's so nuanced that you really want to be careful just throwing it around because that's exactly why we see busts in the top portions of the draft. Exactly that attitude.
You don't think anyone asked Nail Yakupov to remove his head from his ass? No one thought of that? haha they just silently went, "well, this isn't gonna work...too bad. Did we keep the receipt on him?"
And yes, Eiserman has a shot that's difficult to teach at this point. I agree. But you can improve your shot too. And that's a technical development piece, which can have a little bit more wiggle room. "You can't teach that shot!" Yeah, maybe not. But have you spent a day with Tim Turk? He'll change your life in a week haha