I like your thought process here.
@justaBoss is correct, Tuch is fast and has an affordable contract for the next five years
@GenW and
@sabres89 make good points that Jones, Zac does not fit into the Sabres future and it is unlikely the Sabres will retain that much.
In essence you are trading Jack for:
Drouin, Jonathan
Fiala, Kevin [RFA Rights]
2022 1st round pick (MTL)
2022 1st round pick (NYR)
2022 2nd round pick (NYR)
I am presuming you view Drouin as a partial cap dump and Ranger first is for the retention, then over all the final pieces are reasonable close to the value of Jack.
Six picks in the first two rounds of next year is very interesting.
I actually like your defense line up. Just four years ago Butcher and Miller were enjoying 40 pt. seasons and Hagg was the future of Philadelphia's defense.
If the Sabres had a decent GK and other pieces fell together, I could see this team in the hunt for most of the season, that is unlikely.
I have been disappointed since Murray sold the farm for Lehner, Kane and O'Reilly. The Sabres never won more games than they lost.