Mate, if I have to say I love someone in football, it has to be the guy who can initiate attacks and control the game from the deep. The regista or DLP is the first I include in my tactic. Who doesn't want a Xavi, Pirlo, Makelele or a Herrera, eh? This guy has to look for a pass and should have the ability to execute the pass(long/short). So a DLP is absolutely important in any tactic and he must be instructed to play more direct passes. The CM(D) must pass it short. He should win the ball and feed it to the DLP. The wingers you have employed play in the traditional line and are not high as they usually are(say as in a 4-2-3-1 or a 4-3-3). So they have to attack as Sambo had mentioned. Your DLP has 2 options along the wings. Hence u have to "exploit the flanks" for a good wing play. They are the ones who can cause a lot of damage in this tactic now. Now coming to the front 2. Well, in a possession tactic I am a little skeptical when it comes to using a Shadow striker. He is a decoy player who does not support and is the main goal scorer. So he is quite pointless if you use a striker with an attack duty up front. A DLP/False 9 along with a SS makes perfect sense. Although, I would avoid that in a possession tactic. The best bet is to use an AP instead of a SS with attack and use a TM upfront who supports. This will help the TM be involved more in the build up play. Also, while the wingers cross, the AP, TM and the other winger come inside the box to score goals. This is why United are successful. In spite of playing possession football, they tend to cross often. This will give something extra to your tactic.
Let me know if it helps, mate.