That's your opinion. I did say I haven't seen either Barnsley or Luton in action, although both have apparently given City a decent game in recent times.
We know anyone can beat anybody else in the Championship. Surprise results happen on a regular basis. For instance, Luton have beaten Bristol City 3-0 this season, drawn with Fulham and beaten Blackburn, Derby and Sheffield Wednesday, while bottom side Barnsley have beaten Fulham and twice drawn with West Brom.
Of course City 'done a number' on Huddersfield. They were terrible, though.