Emery not built for the higher level clubs. He doesn't have the personality and is too boring to galvanise top level players that arent Spanish or mid table level talent.
I don't care how many EL he won. Barca and Real have hired or been linked with every Spanish coach but him. If he was really good Real would of moved heaven and earth to bring him in as coach and they havent. That tells you everything you need to know.
Arsenal are not Real Madrid or Barcelona. Arsenal are not a higher level club. We aren't in 2003. Europa League, Conference League, that's Arsenal's level and it has been for a good 12 or 13 years now. That's the level of competition they can hope to win: domestic cups and lower tier continental cups. Not since 2008 or 2009 have Arsenal ever been in a title race or gone deep in the CL knockouts. Every single top 4 finish since then, they were just in the CL to make up the numbers, to be eliminated in the first knockout round by Barcelona or Bayern Munich. They're no better than Sevilla or Villarreal or the other Europa League teams. Emery is more than good enough to suit Arsenal's level and to bring them realistic success. Arsenal does not have the football heritage, to borrow Mourinho's expression, to be challenging for titles beyond Emery's level for at least another five years, more likely ten.