Not so long ago, Manchester United and Arsenal were almost alligned as the Premier League’s very own ‘Banter Brothers’. One messes up, the other follows suit, and vice versa. Big-money signings flopping on an almost annual basis, very highly-rated managers doing their proverbial nut in trying to shake a sleeping giant from their slumber, and success proved perenially elusive. So how have Arsenal moved so far clear of Manchester United? How have Arsenal got their house in order while the other half of this ‘Chuckle brother’ pairing continues to slip over banana skins and trip head first into th…