Not sure about Carcillo on the 4th line. He's doing pretty well right now, and putting him on the 4th line would mean his ice time would drop.
It's quite possible, Carcillo-Betts-Lappy was always a great 4th/Energy line for us. Carcillo is doing decent, but he's certainly not cemented into Richards line. Possibly I could see him being put on the 3rd line with JVR-Giroux