There's a thin dividing line between confidence and arrogance. He crosses that line. He's told the Macclesfield players they have got one of the best defenders in the world now managing them. Well I've news for them.
He wasn't even one of the best defenders in London - He was a very fine player. But great players don't always make great managers - see Dannie Bulman article on Tony Adams for more proof. He may well get some success at Maccesfield - it helped Paul Ince forge a career in management until the wheels came off at Blackburn
It's also (despite what others say) very low risk. If it goes wrong he will blame everything but him (lack of resources, poor players, race) whereas if it goes well he will soon be poached by better clubs than Macclesfield.
I can see lots of Harry Kewell in him - someone has given him a chance - he'll look for the first exit point possible and then it'll go wrong and he'll be on the management scrap heap.
Management is far more brutal than playing professionally