I present season 2013-14 as evidence he can manage.
What's the agenda here? Get rid of Martinez? For who? Who would you replace him with?
Martinez took over a side that was finishing 5th/6th and he managed to replicate that feat during a 12 month long honeymoon period. He has subsequently totally mismanaged our squad, and we have been set back years a result. That honeymoon period has gone, and the likes of Lukaku and Mirallas have now seen enough to want out, they don't want to wait around and see if Roberto Martinez can undo his horrendous mismanagement over the last nine months, they just want out.
Everton are capable of getting a manager better than Martinez. Martinez is not the best that Everton can manage. Loads of managers would be interested in taking over his job, loads of them. But if you are pushing for specific names, then I would say Steve Maclaren, Mark Hughes, even
Moyes.