first: I really don't want to go into the details, but as I said there was more to the difference between the different sides between the 4- and 13-defenders. Just wanted to point out there is some difference.
And ball possession does of course not directly correspond to shots.
third: I really don't understand why so many people here insist on 3-5-2 being discriminated on ppm or something. Of course one shouldn't play it if one has to rely on a strong defense and no tactic is suitable all the time.
But it can have it's benefits. Like take a look at my recent league match:
soccer.powerplaymanager.c...
I have to note that I was never beaten up more thoroughly, it was the highest defeat with the most number of ST against me by far. The opponent isn't much better than me but just outplayed me tactically (and his players were in quite some crazy form). I heavily lost another match against 3-5-2 this season. So if you put in two drawn-in side defenders and are able to control the midfield through your advantage of having one more player there, you can profit from such a tactic.
It's just not a good idea to leave the side defense wide open.