Jose Mourinho, in his second coming, is seen constantly trying to bring back his 4-3-3 which worked wonders during his first reign. The formation was solid in the back, which made conceding almost impossible and scoring facile utilizing the strengths of the players at that time. Here's why it just might not click with the players we have now.
What Jose had then,
What he has now,
4-3-3 is all about the attacking trio spreading the play wide and the defensive trio playing close enough to hold the back. The Makelele position is almost irreplaceable for now, with Mikel the closest we have there. MvG needs time before getting there, or he just might be a box-to-box midfielder rather than a proper DM. Of that trio, Lampard/Oscar and Ramires are always on the look out to press forward and we'll have a tough time defending counters from pacy forwards, with only Mikel supporting Luiz(?) and Cahill.
As far as attacking, 4-3-3 depends on good crossers and a target man striker who's an aerial threat, as most goals come from the air. Our strikers Eto'o, Torres and Ba for all I've seen seem to constantly drift wide in support of creating a chance along with our midfield rather than position themselves in the box and wait for a cross. As of current form, none is in comparison with what Drogba was, as a targetman. Considering the service, the cross success/attempt ratio of our wingers and wing backs in the recent games:
Ivanovic: 0/4, 0/4, 1/9, 1/4
Cole: 1/2, 0/1, 0/1, 0/0
Schurrle: 5/12, DNP, 1/3, 0/0
Hazard: 0/2, 1/4, 1/1, 1/3
Oscar: 2/14, 0/3, 0/2, 0/1
Ramires: 0/3, DNP, 2/4, 0/1
Horrifying? While Ivanovic's cross attempts have been a pain to watch lately, Cole has almost stopped crossing at all. Azpilicueta might help in this regard but too much dependence on one wing curtails our attack options. Our attacking players have not been of much help either on this. So I think the best way to utilize the current squad is the 4-2-3-1 playing on the ground, breaking defences with creative passes or a 4-1-4-1 with all our midfield talent put into force. That was Mata and Oscar get to play central. Abundance of service for the striker. Players like Hazard, De Bruyne and Schurrle who can track back out wide will help defending too. One way to make use of all our talent.