I know that it is not the most popular formation in the world but before you dismiss it entirely, consider it with the current personnel we have at Tottenham.
In terms of CBs, when everyone is fit, we have a very healthy selection of quality defenders. Even excluding Woodgate, who sadly looks finished, we have King, Kaboul, Gallas, Dawson & Bassong to pick from, & Charlie can play there also & might even do a better job in a 3 rather than a pair.
1 thing that makes a 3-5-2 effective is having a pair of proper Wing-Backs. Wide players with plenty of energy & are equally adept at getting forwards as they are dropping back to defend. On the left we certainly have arguably the best potential WB in the Premier League with Gareth Bale. 3-5-2 formations are oft criticised because they become disjointed toward the end of matches when the wide players begin to tire. It requires tremendous amounts of energy on their part when they are expected to run back-and-forth the length of the pitch for 90min. However, Bale appears unaffected & is relentless in his forays forward & is repeatedly seen driving at the opposition's RB right into injury time. I would suggest that Bale is perhaps the perfect wide player for a 3-5-2 & that our lefthand side would be sorted.
The right is deffo more of a concern. Lennon, altho better than other RW in the League at realising his defensive responsibilities, is a long way from being a WB. I still think, however, that when he is on top form he is so dangerous in attack that he pushes both his opposing LB & often his LW all the way back so that they can double up on the threat of his pace. Other than Lennon we are a little bit short on the right. Charlie is far too slow & defensive to work as a WB & Bentley is just as lightweight in his defensive duties as Lennon but does not offer that same pacey threat capable of pushing the opposition back which Azza does.
That then allows us to play 2 CMs as well as an AM. Van der Vaart can take his favoured AM role & be behind a proper strike pairing that way. We would be lethal going forward, with the deliveries coming in from the flanks from Bale & Lennon, Crouchy winning the headers and either Lennon or VdV tucking them away. I could see us playing large portions of the game in the opposition's half & we would have 3 CBs mopping up whenever they try to hit us on the counter.
ESPN: Could Spurs switch to a 3-5-2?