So Norwich then, in your view. I probably agree. Certainly we don't have a recent history of problems against them, except 2012 away, IIRC.
I think there is some evidence accumulating about the advantage of not having midweek European games. Chelsea and Liverpool have benefited this year. Liverpool the other year, and Spurs have picked up form since the end of the group stage.
Southampton will be playing twice a week for three weeks. We'll be playing once a week. I don't think it is nonsense to suggest that tiredness could be a factor.