I'd like to know whether Larsson was open to returning or not. It's not all the choice of the teams when the players are able to pick their own destination. I liked him but his ceiling really is a fourth-line center. He's a good one but Buffalo just re-signed Lazar and likely is looking for him to take that spot over after a season in which he was called up from the minors and played well enough to earn an NHL job next year and a new, multi-year contract. Lazar played well last year and came cheaper than Larsson so I have no issue with letting Larry walk if I'm Buffalo.
As for Eakin, I think the Sabres intend on him centering the third line. Buffalo has had huge holes at center on both the second and third lines for the better part of two years now and Adams seems to have wanted to address both with the trade for Staal and this signing. Despite a down season, I believe Eakin can hold that kind of role, as it's the one he's typically played for a majority of his career. He's only a season removed from a 22-goal, 41-point season in Vegas playing a similar role so I have no doubt that there's a chance he can still be productive there. I don't see him as Larsson's replacement. He's a better offensive player than Larsson and Lazar and can play third-line minutes effectively while contributing depth scoring that the team has lacked. The Sabres have played players like Casey Mittelstadt and Evan Rodrigues there regularly for the past few seasons, clearly out of their ideal roles. Eakin is an upgrade and the price is reasonable. Buffalo should be content with this.