Doesn't matter if he is or not, if he's not played he won't improve and won't reach his potential.
In terms of achievement, Campbell eclipses most all of our young players for a while now.
I don't think we really could afford to give TWO young striker enough play time for development, especially when there's Ayoze.
I got your point, that's why I was shouting for Vuckic a few years ago. But this doesn't apply to Campbell imo. Campbell failed mostly because he is "comparatively" not good enough, from the limited time on the pitch. Armstrong's touch and football sense are a lot better and he deserves to get the limited play time left out by Cisse and Ayoze. Campbell has to prove his value on loan - like Dummett - and if he failed, that's it. This does not relate to whether Pardew is the manager or not.