Guerin hasn't contributed positively to this current roster in any way. When he was hired he inherited Kaprizov, Fiala, Boldy, Suter, Zuccarello, Spurgeon, Eriksson Ek, Foligno, Greenway, Brodin, Hartman and Zucker. He inherited all of those, he didn't acquire any of them himself.
He has since removed a few of those guys without bringing in any suitable replacements. Zucker for Addison and 1st might go down as his least bad move, depending on how Addison keeps progressing and how Lambos turns out.
The rest of his "successes" have been a result of hiring a scout who seems to be good at his job.
The other guys Guerin has brought in via trade during his time here:
Galchenyuk- non-factor, already gone
Bjugstad- non-factor, already gone
Johansson- non-factor, already gone
Nick Bonino- non-factor, already gone
Ian Cole- non-factor, already gone
Nolan Stevens- AHL forward, non-factor, already gone
Brandon Baddock- AHL forward, non-factor
Tyson Jost- non-factor, soon to be gone
Nicolas Deslauriers- non-factor, already gone
Jake Middleton- good bottom pair defenseman
MA Fleury- average starting goaltender (to replace another average starting goaltender)
Filip Gustavsson- let's call him an average backup goaltender (to replace an above average backup goaltender, ultimately)
That's not even getting into the fact that the best player he's signed via free agency is a bottom six player that's been forced into a top six role he clearly isn't good enough for.
He gave Goligoski 2 more years and a NMC, now Goligoski is the 7th D getting healthy scratched every night.
Kulikov was overpaid and then promptly shipped out for nothing.
This is a guy who said "it's about f***ing winning" but then hasn't done anything but strip down what should have been a perennial playoff team to it's most basic components, resulting in a fringe playoff team. He has yet to demonstrate he knows how to acquire NHL talent. He is going on his fourth season as an NHL GM, he no longer gets the benefit of the doubt or the "wait and see" approach.
I'm fully aware that he is not on the hot seat until the buyouts are over and Kaprizov leaves, but it's crystal clear to see that he is not the reason for this teams success, and neither is the coach he extended.