Separating heroes from villains in the great retail survival struggle is like spotting bent coppers in Line of Duty — whose sixth series, I’m pleased to report, has just finished filming. The plot just keeps twisting. Sir Philip Green, as I said last week, is seen as an irredeemable baddie; and most commentators (though not usually me) put sportswear tycoon Mike Ashley in a similar category, as an opportunist with a track record as a harsh employer.