Thing is though, despite both being 'pop' they're very different musically - diametric opposites in fact.
In the upbeat anthems vs moody goth pop stakes they're about as similar as The Killers and The Cure.
If Macca and his band are doing Glastonbury as a one off as a "friends of the festival' type deal - why wouldn't they switch nights to help the organisers settle the line up?