I think i would rather let Kelly play the fourth line, but from time to time when you need extra defence, you switch line for Kelly with Pageau and Pyatt. Dzingle-Pageau-Pyatt Kelly-Lazar-Neil With Lazar and Kelly switching depending on faceoff side. At some point, if Pyatt regress Than Switch Lazar and Pyatt. Kelly return to center. Of course, Lazar have to prove he can handle 3rd line minutes, and contribute.