Of course. However this thread is about the value of Power. Clearly the Sabres have a 1D in Dahlin. If they value Power as also a 1D and can get a value in return that reflects that, then it’s a wise trade. However if the market sees Power as a 3 and the value of the return reflects that, then the Sabres have a big decision. Do they keep Power, who they believe is a #1? If they do then they have, in their view of value, two #1 D.
The Sabres, imo, are in no position to have the luxury of two #1 D, when clearly they are in need of better players in other roles.
if Power is valued by the Sabres as a #3, then they wouldn’t trade him because, as you point out, it’s good to have more than two top four D.