I don't pay that much attention to other teams, but I'd say no-one else plays like we did when Christie was fit. We played an asymmetrical shape with the ball, where Greaves at LB tucked in to become and extra midfielder, while Christie was way upfield wide right with the RF player coming inside to make space for him. By Greaves being more central it meant that when he got the ball he could pass to the wide left player who had a chance of going forward. When Elder played LB he would hug the touchline which meant that even if he could get the ball forward to the wide left player, that player would be taking it facing our goal so there wouldn't be much forward progress.
I thought that style worked well, and Christie scored or created a few goals. Add that to a fit Traore and an LB who can get forward (which Greaves did) and beat a man (which Greaves hardly ever did) and it could be an effective style. If that's enough to justify describing us as unique is another matter, the full back tucking in is a Man City tactic but I'm not sure I've seen other Championship teams doing it.