Personally I dont like playing TM alongside with a poacher. It is more suitable with a counter-attack type of tactic. When facing a weaker opponent and having dominance in possession, it is much harder to break through opponent defence line. One good example is the match between Liverpool and Tottenham several weeks ago. Andy Carroll and Belamy were put in front, forming a TM support-poacher partnership. Liverpool has 55% possession, all the cross from wingers and full-backs were connected well with Carroll but they still struggled to find a break-through. When Suarez was brought in, forming a trequatista-TM attack partnership with Carroll, they played much better, created more chances as Tottenham CB had harder time to mark Suarez, and Carroll was left with more space.
In Mancity formation, Dzeko position is always inside penalty box. Mancity using 3 AM behind Dzeko, moving and passing around more freely to distract and create holes in the opponent's defence line. If Dzeko can gain some space, he would be in perfect position to score, if he cannot lose his men, his movement also would help create space for Aguero to dribble through.
So with that thought in mind, I will try create some tactics and experiment it in friendly matches in Jan to see how it would work. As indicated before, my tactics would be built around 442 formation, so any suggestion about how to set instructions and roles for players is welcome :).
PS: here is my Carlos Fierro for sporting_23