I'm Irish and consider Moz to be way more English than Irish. He has Irish roots and hasn't forgotten them and grew up in that Irish support system in Manchester. But his formative years were in England. But surely Moz is more global now - having lived in Manchester, London, Dublin, L.A., Rome, Switzerland, not to mention the countless days & nights on tour across the world. I think it's more important how Moz sees himself, not how we decide what nationality he is. I would say that the Manc culture/outlook is closer to Irish than English. I say that having been to Manc and having Manc friends here in Ireland who would consider themselves Irish Blood, English Heart. However, if you asked me if Moz is English or Irish I'd have to say English. Most of the best music in the world (ever) came from England, in my exalted opinion.
Joy Div, The Smiths, Moz, The The, Siouxsie, New Order, The Cure, Depeche Mode, Suede, Echobelly, Blancmange, Gary Numan, The Beatles, The Stone Roses, Oasis, Bowie, etc. US has some great artists too of course but England (considering its size) produced genre defining/breaking music.