This could make alot of sense for your team moving forward as Aho may also only be a C in the future.
Id start with Schief for skinner/Klingberg which helps you this season and gives you another no 1 d keeper. If he pushes back with those two for pettersson I'd ask for a draft pick upgrade and probably be fine with it.
I mean you really don't want to be keeping 3 centers in a keep 6 and as is you'd have to.
Matthews
Laine
Kucherov
Schief or Pettersson (whichever you keep)
Klingberg
Krug or Aho
Pretty solid group going forward no matter how you slice it but I don't want all 3 centers if it can be avoided. I'd rather move schiefele gun to my head than pettersson so don't be afraid to shop Schief to other GMs for a LW/D combo.