I actually suspect that a Nylander/Kerfoot line would rival the Tavares line in terms of playing time. Who is the 2nd or 3rd line would be blurred. The Nylander/Kerfoot line may get more minutes than Tavares line some nights. Plus, Nylander and Tavares should see PP time, whereas Kerfoot will see PK time.
They know Nylander/Kerfoot works so if they can get a Tavares line producing, they are thinking they would have 3 good lines. Tavares has a history of not needing great players to be productive. Bunting seems like the kind of player that would mesh with Tavares, and Ho-Sang is there because they probably think the only way to keep his head on his straight, is playing with Tavares.