Not at all clear that 6-12 next year won't outproduce Lafreniere. Some may, some won't. But, it's also whether or not they can deliver similar / better performance cheaper.
In a hard cap world, there's a constant need to optimize performance per dollar spent. Your offer sheet approach doesn't do that.
The major (repeatable) sources of outpeformance seem to be: ELCs; betting early on rising stars (Hughes, Robertson, etc.); and top stars taking less and overachieving (MacKinnon for years, Marchand, etc.).
With Lafreniere, you're talking about scenario 2 (betting early on a rising star), but - if bet correctly - you're setting it up so that Laf can renegotiate in a year to get more money.
If you're going to make the bet, you need to do so in a way that the upside is worth the risk.