Not sure I agree with that. The way our team is set-up is clearly helping Grabban somewhat, but the lack of goals/chances for Redmond, Lafferty and Hoolahan would suggest it isn't doing them any favours (early days yet admittedly). If changing the set-up can help the others to get on the scoresheet, then I'm all for it. If Grabban is our only serious goal threat then it's much easier to mark him out of the game, and we'll struggle if he has an off-day or dips in form. But if we have Lafferty, Redmond, Grabban and Hoolahan all getting into good positions and netting regularly, then we're much more difficult for the opposition to contain, and less dependent on a single players performance.
Whilst it's 5 goals from 5 for Grabban, it's also the same number for our whole front 4. If Grabban moving into a slightly different role means our front 4 score 6 or 7 in 5 games between them, then I'd say it's worth the change.