I think it depends on the role. ZAR and Malgin, for example, have played very well with Kampf on that 4th line. More often than not, they are dominating possession and generating really good opportunities. It sucks that ZAR hasn't been able to finish some of them, but they do a lot as a shutdown line.
The issue is that the 3rd line is very similar, but not doing as well. They are getting outplayed more often. They are not starting in the defensive zone as often, although still starting there 2/3s of the time. And they are struggling to put up offense when they are supposed to be a 2-way line. I think 2/3 of Kerfoot, Jarnkrok, Holmberg, and Engvall could work together, but they need that 3rd guy who is a true center to put it together. Or at the very least, do your best by having Kerfoot and Jarnkrok split draws and have an Engvall-Kerfoot-Jarnkrok line. Kerfoot is fine as a center other than his faceoff ability, and that combination is one that has actually worked for Jarnkrok.