I'm starting to be open to the Barba to 5/8 idea. At least until he can get confidence back in his bung leg. He can't be any slower than Hoffman, the question will be can he half-break as many tackles through strength as Hoffman does. If so, he's be much better at getting the ball away in traffic. He's already said that he's being utilised more for his ball-playing this year, whether that's because Hoffman sucks or because his leg is not 100%, who knows, but put him in the position to at least use those skills on a whim.
Here's my take on the Gillett to 5/8 possibility which only one person (I think) has mentioned but is a genuine option. He'd actually tick most of the boxes in attack, be it running game, short kicking game etc, and he went kind of okay against the eventual premiers of 2011 (we lost because of bull**** ref calls, I'll maintain that to the grave). But his lateral defence will be his downfall in the position. We've already seen Hoffman get caught out laterally multiple times, with poor decision making, and not covering the inside. Gillett will be even slower again. With the game speeding up, it'd be asking for trouble IMO.