Frankly I think many GM's could have done exactly what he did. It's not particularly hard to acquire bottom sixers and not trade your picks while already having a playoff caliber core.
That's cause there wasn't much else to do. He inherited a team that was stuck.
He has done decent on a lot of fronts:
-signed Hartman 3x$1.7M
-signed Eriksson Ek for 8 years at $5.25M
-signed meaningful role players to cheap contracts (Johansson, Gaudreau, Merrill)
-boosted the prospect pool, you can say they are a bunch of 2nd liners/2nd pair guys and I mostly agree but the prospect pool is significantly better than where it was and we have at least one player at every position that people can feel good about (for me it is Khusnutdinov - C, Ohgren - LW, Yurov - RW, Lambos - LD, Spacek - RD, Wallstedt - G).
-had an excellent trade deadline acquiring players that helped push us into the playoffs while Kaprizov was out
-turned Jordan Greenway into pick 64 (Riley Heidt)
-traded a 34-35 year old goaltender for a 24-25 year old starter quality goaltender
-signed Boldy to a long term extension that should look like a steal in a couple seasons when the cap spikes
-moved on from Dumba, whom has needed a fresh start for a couple of seasons at least
-reinvigorated the locker room with trading a 5th for Reaves
-turned a backup goaltender in Kahkonen into a serviceable 2nd pairing Middleton
-Pateryn for Cole was a steal
-Turned Kunin and mid pick into a better player, a 2nd and a mid pick
-Zucker for Addison and a 1st (Lambos) was pretty good value
I just don't view the sum of this as an average Joe GM would have done the same thing. A lot of these moves are pretty smart and calculated because that's the way they have to operate while still dealing with the Parise/Suter contracts. The real test for Guerin as a GM comes in the 2024-2026 time frame when the cap goes up and the buyout dead cap drops significantly.