I think that's exactly what he was doing, fully intending on switching to someone else once they put their hand up (White, McDermott, Bell and McReight being the obvious candidates)I said it at the time but geez Slipper/MHooper co-captains was such an awful call, there's no way Eddie didn't know Bell was a far superior player and that MHooper (even injury free) was very non-secure in his position.
The only explanation to me is he did it to see who else stepped up in a leadership role, it's kind of smart really, give the captaincy to two veterans rather than make a rash decision before he's fully evaluated other candidates properly.