Quoting: Leafsfan98
First, Rati is an A tier prospect, he could have easily gone 1rst but an off season caused him to go in the 2nd round. Second, Blais is another A tier prospect which equates the value. Skinner is another prospect instead of Beaulivier and the 4rth was for Mikkola.
Obviously Tarasenko wasn't going to get Horvat's package but this is still a pretty good haul for tarasenko nonetheless. The Hagel trade was a stupid trade on Brisebois' part and shows how much better of a GM Yzerman is compared to Brisebois
Blais is not an "A Tier Prospect".
He is nearly 27 years old with multiple seasons under his belt. He showed some promise in St.Louis but played poorly in the Rangers system. He is a cap equalizer who likely was attractive to St.Louis in the context of having to take back some cap/a contract because they will need NHL bodies past the deadline and he played his best hockey for them. The realistic best case scenario for him is that he makes it as a third liner on St.Louis, but even that isn't guaranteed.
Raty is not an A prospect. He might have been the Islanders best prospect, but that's more a consequence of their poor drafting. He's your typical teams 4th or worsts best prospect that gets moved at the deadline. Someone who has some upside, but they aren't a sure thing star. The fact that he was originally pegged as a first round talent is not a positive. It means he was a faller. Fans tend to have a very strong bias towards fallers, but in reality fallers are almost always more Sean Day than they are Jakob Chychrun. Someone falls out of the first round because their development stopped, or went poorly.
The Hagel trade was cap motivated. If Hagel was a pending UFA he would have maybe gotten a 2nd and a B Prospect based on the prices last year. Using Hagel as a comparison doesn't work, because his entire value was predicated in his contract. He was cost controlled for 2.5 seasons at a 1.5M AAV. That was as a player who at the time had established himself as a top 6 forward. Tampa gave up extra picks to get a 4.5M player for 1.5M. The only possible comparable situation at this deadline might be Jakob Chychrun, since he is signed at 4.5M for 3 years, and a comparable top pairing defenseman would cost 6-7 million. Even then, that isn't as drastic as getting a 2nd line forward for an almost replacement level cap hit.