I never looked at it that way in terms of a compensation pick. But I still think it would be a ballsy move for a gm to pick a kid that small in the first round. If he busts or doesn't turn out to be the second coming of Fleury or St. Louis, that GM will be hearing about it for the rest of his tenure, especially if players after him turn out to be studs. I mean, you think Glen Sather likes watching Claude Giroux light up the league knowing that he took Korpikoski right before him?
Also, it would be kind of foolish to take a kid in the first if there's a good chance that Grimaldi could slip into the mid to late 2nd round because other teams are scared off of his size. Take Tim Tebow for example: if the Broncos picked him in the third and used one of their first rounders to take like Dez Bryant or something, then a.) the team is more vastly more talented and b.) Tebow wouldn't be a gamble if you took him in the third round like everyone predicted he would go. Instead Josh McDaniels is sitting in the unemployment line as one of the worst hires in recent NFL history.
So if Grimaldi slides, he will has reasonable expectations associated with his performance, the GM doesn't chance his reputation to a high stakes pick (which it is when you take a kid who's 5'6 in the first round), and the GM looks like a genius if Grimaldi does turn out to be the next Fleury.