Yes their GD is too good.
Permutations
Wigan
If Wigan lose against Arsenal they are relegated.
If Wigan draw at Arsenal, Aston Villa are safe.
If Wigan win at Arsenal and win against Villa, Wigan are safe. Aston Villa
If Wigan win at Arsenal, Villa lose to Wigan and Sunderland don't lose to Spurs, Villa are relegated.
If Wigan draw or lose at Arsenal, Aston Villa are safe.
If Wigan win at Arsenal and Villa don't lose to Wigan, Villa are safe. Sunderland
If Wigan win both games and Sunderland lose to Spurs, Sunderland are relegated.
If Wigan draw with Arsenal and Win against Villa, Sunderland need to draw at Spurs.
If Wigan lose against either Arsenal or Villa, Sunderland are safe
Thank you for clearing it up so what you said that true.