Nameless I don't think Wagner's explanation holds any water.
Is he giving players 3 weeks off ? Or is he going to play his full strength team this weekend in a dead game ?
The point about the performance in the other 44 games is irrelevant , Waburton has not been Forest manager all season so how he could have done better over 44 games is hard to see. He came in with a tough job and a fellow manager has made it harder by breaking the rules, and the spirit of the rules. Mowbray likewise at Blackburn.
And this is where the chances of any meaningful punishment other than a token small fine can be dished out by the authorities, in a squad game how they can they possibly be in a position to accurately judge what the strongest team of any given club is on a particular week, before you fudge the discussion further injuries,"slight knocks" "felt something in training" type excuses/reasons.
I remember everyone's favourite village idiot, Ian Holloway, relying on this when he was manager of Blackpool in the Premier League and made 10 changes against a top four side in a game he thought they had no chance of picking up anything from, and resting his team for a more important and winnable relegation six pointer in the next match. He got very uppity with the description of "second" team when interviewed but that's what it was as all his first choice players played the next week.