A pretty good list to be fair! Pixey is really good too if she fits into your other plans, I'm loving her recently released album.
Royston Club, Chloe Slater and Overpass also, as others have mentioned
It's a great little day festival, we're heading over for it too
Only headliner bands confirmed to be doing European fests so far are Green Day (Southside), Biffy Clyro (Rock Am Ring and Southside), Sleep Token (Rock AM Ring) Slipknot (Rock Am Ring and NovaRock), BMTH (Rock Am Ring). Think this is all.