Arsenal’s Mikel Arteta is perhaps best placed to fill the void but the coaching contenders are legion as another season looms This used to be a land of giants. This used to be a land where big men fought. This used to be a land where Sir Alex Ferguson and Arsène Wenger tussled, then José Mourinho joined the fray. This used to be a land where Jürgen Klopp made Pep Guardiola reconsider, and he changed his style and won anyway. Not any more. Next season will be the first since the inaugural Premie…