Some players have better instincts and sense of timing on a footy field than others. I think those are particularly important for forwards. No doubt the best backmen also have that innate sense of the game, but at the end of the day with a defender you can always say 'stay on your man', and make it simple, and most of the game is coming from ahead of you. You'll quite often see players who pick the game up late starting in defence (examples being Falou at GWS or Kennelly for Sydney).
Logue might have fantastic instincts for all I know, so perhaps he's a chance to be a good forward, but I think you'd start by playing him down back for a while to learn the game. Our backline is full of smart footy players to learn from, and I reckon a bit of chaos down in the form of Logue would be great.
That said, Lyon did thrown him forward at times last year. It didn't work very well, but Lyon either thought he could contribute down there or was desperate enough to try it.