Sorry for the late reply and thanks for the detailed response!
Before the update I usually used "butterfly formation" but since DML/DMR got removed and the results against really weak opponents were quite disappointing I changed to 451-V. Not sure whether this season is better because I already had two troll results in my league but at least my three offensive players are performing better. ^^
Well, let's see. I have the feeling I'm not "getting" this game anymore (regarding tactics and formations). But if there is a logic behind that and I have the chance to adept it's alright. Before last season I usually sold my players age 22 or older and only tried to stick to younger ones. But since then I kept 6 22-23 players and pushed them with green packs and training but they were really bad. And they are still not as good as they where or probably should be.
If this season is disappointing I will sell all 22+ players and try to build up a new fresh team.