What about Mark Ronson for the Sunday Pyramid sub? He subbed the Other in 2015 and only played a DJ set/guest slots (Miley and King Princess) last year. This year he's playing Sziget in a high slot and doesn't have many other dates announced so could easily appear at Glastonbury. Could bring out some special guests too e.g. Lykkie Li, Lilly Allen, Boy George, Alicia Keys etc.
Sunday is a nightmare! The Loyle Carner & Billie Ellish v Miley & Vampire Weekend is a horror show. Then Janelle v CATQ v The Streets v The Cure clash is unforgiving as a lot of the main stage Friday and Saturday headliners I'm not bothered about. But its Glastonbury so c'est la vie