A lot has been made of Treliving not lottery protecting the first round pick that we traded for Hamonic - with the current standings, that pick has ~10% chance to win a top-3 pick (based on
this source), though Calgary might drop a couple more spots in the standings so it's possible that the pick might have up to 15% chance. According to
this page, a top 3 pick is basically guaranteed to be a regular NHLer with an 80% chance of being a top 6 forward/top 4 D/starting goalie (lets call that an impact player). The #10-12 pick seems to have a ~33% chance to land you an impact player. So taking a simplistic approach, a non lottery-protected pick would have 38-40% chance to land you an impact player, meaning lottery protection of a first round draft pick in that range should be worth a 5-7% chance to get an impact player.
From that same TSN table, that seems to put the value of lottery protecting this particular 1st rounder as likely a #90-100 pick - so say a late 3rd rounder or 4th round pick. As a GM, would you offer an extra 3rd or 4th round pick in return for being allowed to lottery protect your 1st round pick that you're trading, in order to get a deal done? Would you offer a 5th, 6th, 7th? As a GM, what additional pick would you ask for in exchange for allowing a 1st rounder to be lottery protected?
Of course this is assumes that the 1st round pick ends up being a lottery pick with a decent chance of winning - the lowest odds lottery pick has just a 3% chance of winning a top-3 pick, though conversely it is possible that you end up with a disaster season that leaves you with a 50% chance.
This simplistic analysis also doesn't take into account "generational" players, deep drafts vs. shallow drafts, etc. - nevertheless, for a typical draft it is likely that even a 4th round pick is an overpayment in order to lottery protect a 1st rounder in most cases, especially considering that if you are trading a 1st rounder you likely aren't expecting it to be a lotto pick. Still, might it be worth it to save your fanbase the anguish of "losing" a top 3 pick? It's possible for that 4th rounder to turn into a Brodie or Gaudreau - but the fans would never know what we missed out on if we trade that pick, and its far more likely that it would turn out to be nothing anyway.