Fantastic managers don't get relegated and sacked two seasons in a row.
He might become fantastic, although I think that will never happen, but he certainly isn't considered a fantastic manager by anyone but the few.
He has won a couple of crap trophies, been relegated and sacked, basically his reputation is worse than martinez when he arrived (Martinez was linked with jobs such as united, The RS etc before he moved to everton, did a fantastic job at swansea, won a big trophy at wigan of all clubs).
Basically he is a crap version of martinez U.N.O.
His defending is just at bad as martinez, but he isn't as good at setting up an attack, isn't as charismatic and genuine as martinez, by all accounts he is disrespectful to his clubs - going missing for 3 days, quiting when it gets back or as soon as the first offer comes through. I mean the guy averages less than a season at a club the last 4 years!
meanwhile martinez (forget all the bad things in terms of management) was a gentleman who respected his clubs and represented them in the correct way and actually tried to build teams.