Here's how i'll define the negative impact spread across 4 larger facets:
1. Created a Hole at 2C
A Top-6 center, under contract in his prime, is one of the most valuable assets in the NHL and such a driver for on-ice production. Removing a Top-6 center without being able to immediately and adequately fill the roster spot has been such a large contributing factor to the losing the past two seasons.
2. Impact on Remaining Players
Created a giant hole in the lineup that pushed several players out of their ideal roles and playing above their heads. Largest cumulative impact was the disturbed development of Casey Mittelstadt & Tage Thompson. We can also assume that not having a solid second line had negative impact on the trade value of all Buffalo defenseman, which we can assume are being shopped to try and fill that Top-6 Center hole.
3. Misuse of Cap Space
By taking on Sobotka (and lesser extent Berglund), JB was not able to capitalize on cleared cap space from moving O'Reilly. Cap space is an asset and allows for transnational flexibility. He basically made a bad move in terms of value-in vs value-out AND handcuffed himself. I thought not paying ROR was one of the big reasons for moving him? But paying Sobotka and Berglund was a good idea?? wtf.
4. Extended the Losing
As you stated, trading out one of their best players made the team worse in terms of wins and losses. Tag that onto prior years of losing, the trade has likely compounded the losing mentality and fragility in the lockerrom and fanbase (that's gotta be some kind of a thing, right?).
I hear you that the Avs survived trading ROR, but our extenuating circumstances and return were much worse.
And I'm not arguing that this trade, on it's face, can't be overcome. I just can't think of a worse move for any organization than the ROR to St Louis deal. A competent GM, along with his professional scouting staff, should have seen this coming and pushed back on any orders from higher up (if they did get marching orders from Pegulla).
5. Pipeline Asset depreciation
We invested 4 “high end futures” in ROR and got 2 back when we traded him 3 years later. There are going to be holes in the pipeline when you acquire great players, but there shouldn’t be when you trade them.