Because Naughton plays such a high-pressure game and attacks defenders like a madman we can sometimes get away with four talls up forward. Substitute Bruce for Naughton and it wouldn't work I think.
Brucey is not too bad with defensive pressure. Well he was certainly decent pre-knee.
You could maybe go Naught, Bruce, JUH and Schack if you only go Keath and Gardiner. Schache has scope to play all 3 spots on the park, so that may work.