Structurally, I think the Sabres roster is sound.
Centers:
Scoring center: Thompson
2-way center: Cozens
Defensive centers: McLeod, Lafferty, Krebs
Adams has some flexibility here as well. Helenius may end up a Sabre sooner than later. That could set up the Sabres somewhat akin to the Panthers, with Thompson, Cozens, and Helenius up the middle, making them tough to play against. That could bump McLeod to wing or even as the 4C. Which may seem bad, but remember that players like Marcus Krueger at 4C make teams really hard to play against.
If Ostlund develops, it could give the Sabres some seriously enviable center depth. Imagine a center spine of Thompson, Ostlund, Helenius, and McLeod, with Cozens available as a winger. If there's a criticism, it's that they don't have the creative playmaking center.
Wings:
Scorers: Peterka
Playmakers: Quinn, Benson, Zucker
Power wingers: Tuch, Greenway, Malenstyn
Defensive: NAK
I think the team is set up fairly well, but I'd love for them to have another power winger high in the line-up. They still don't have that net front presence who can bang in goals and help a power play. But overall it's a decent group with a lot of potential in the development of Peterka, Quinn, and Benson.
Kulich adds scoring punch, Rosen is a playmaker, and Wahlberg could fill the power forward need in the future.
Defense
All around: Dahlin, Byrum
Transition and offense: Power
Defense: Samuelsson, Clifton, Bryson, Gilbert
Transition: Jokiharju
I think this group is in really good shape. Dahlin is the center piece. Byrum could be a tremendous 2nd pairing defenseman if he's not covering for another player. Power seems to be divisive for the fanbase. His transition ability is pretty good. I think he's a better version of Bouwmeester (have since the draft) and if expectations are such, he's a heck of a player. Bryson seems better as a defensive zone player and the Sabres have depth in that role.
I don't know where Jokiharju fits. He may be a wait and see type this season under Ruff. Johnson will be the first call up and he fills the role of the new age defensive defenseman: mobile with a great stick. The organization is deep to D #10 with Clague, so no need to rush anyone.
Goaltending
UPL, Bernier, Levi
Adams doesn't get credit for sticking to his guns with the goaltending, but he should. UPL is a fine starter who will only get better. He's fully transitioned to the new style of goaltending. Pick up Bernier was brilliant. He should not start a lot. Just wear the baseball cap and pinch hit when needed. That allows Levi to play in Rochester and then only come to Buffalo when he's going to start.
Overall, I think the biggest changes will be Ruff and the use of a legitimate bottom 6. I think this roster on paper is about 10th in the conference but Ruff will get more development out of them and they will squeak into the playoffs.