I am not saying this tactic is for you but by watching it may help you understand a logic behind why I structured the tactic as I did.
I, like yourself, can find it frustrating. Best way to test is create a tactic you think is how you want to play, save the game and tactic and turn auto save off. Then go on holiday for the season with "use current tactics" and "current team selection where possible" checked.
Make a note of your results, points etc etc and then re load the game again. Change one thing in your tactic and then do the above again, make note of your results and then do it again and again and again.
By changing one thing each time you will get to understand what makes that tactic better, or worse. You can then start to tinker, piece things together and slowly understand what does what.
You will be very surprised what some things do. For example, I can get more possession by doing with direct passing than I can with short passing. (I know there are other factors as to why you can lose possession of the ball but just an example)
Be warned though. What may look good for a set formation can look different for another. It really is about playing around with different variants for different tactics.
I went through every single formation, style etc etc in thousands of combinations to help me understand. Took me nearly two weeks of automated playing with the same base value team and game save to figure a few things out.
You will of course have some factors you cant control. Injuries and the fact its a computer game, but you are not looking for little improvements, you are looking for massive swings.
Example of a tactic for a good team can b e found in my video here
I am just doing one for Man Utd as we speak. Can get them to win the league on holiday with 86 points and no transfers but want better. Still tinkering.
Hope that helps. Sometimes its better to think in a methodical way than a football tactic way.
One tactic may work for one team, but another. If you have a team you want to play with then happy to try some testing on that team and do a video for you with results.