@Diogo-Almeida Ah, I understand For 17.1.2, it's good I always use defensive positioning match preparation, and then i usually swap between fitness and tactics training during the season. For pre-season, if your team is not cohesive yet, then use team cohesion training. If the team cohesion is really bad, for example if you bought a lot of new players, stick with team cohesion for at least 10 matches into the season, maybe even half the season.
There are several teams that go through a whole season without scoring one goal from corner setups.
Watch how the corner routines work within the match engine, when your team has a corner.
And then change them slightly to improve your teams chances.
Are your corners towards the penalty area, then have a tall strong player challenge their keeper.
No strong corner takers, then make them play it short to a player with good vision and passing.
Those are just a few examples of how you can fiddle with the routines.
Ah, I used some logic to recreate inverted wing backs from normal wing backs, since I like when they play more centrally without them being as broken as "real" inverted wing backs. Then I tried to make a formation I like (the Triumvirat formation is the perfect example). Apart from that, everything is more or less trial and error.
And thanks @MrLangvatn, I'm pretty sure the results will be fun with the Triumvirat tactic
When SI change things and/or fix things. There are no guarantees, that certain changes won't affect the ME in one way or another, even though they don't directly change something within the ME.
Things like how a tactic work, how morale work, how a player instruction work... these are not directly ME code, but do affect the ME.
So while they don't say they changed the ME, some actions/tweaks might have a wider affect.
Plus... Both back in FM15 and FM16, updates that did not change ME, did change how tactics worked.
The only suggestion I can make is to try different tweaks, test for 5-10 test matches, then load to the beginning of those matches and play them again with another tweak, another tweak another tweak. What works well is different from patch to patch, so there isn't any "logic" I can rely on for these things. I know there are many sites that post articles about what roles fit together, and try to add reason behind it all, but this is a game, not real football Trial and error is the only way to make tactics if you want the best possible combinations.
For example, after testing, you find out you have problems in the back... Well, then you try out different things like change the D-line, change the closing down, marking, OI's, roles, player instructions, etc.