You're watching a different Pelle than I am. His heading has been poor every time I've seen him, but his hold up and layoff play made up for that earlier in the season. We're getting pressed in the final third harder than ever now, and that's making it that much more difficult for our strikers to get through defences which are now invariably packed.
That said, I'd go along with giving Shane a run for a few games, mix it up a bit, with GP as an impact sub.