As a conclusion I would like to add that AI managers will easily counter your tactics if you go with the exact same tactics for a prolonged period. Sometimes springing a sudden change in tempo, passing style and/or team shape can give you a nice edge for a few matches until other teams you play...
My specific tactic is alternating between 4231, 451 and 4321. You will be able to quickly adapt the team because the tactics are very similar. And you can easily asess if you are the stronger team and thus deploy the correct risk or safety depending on the situation. Counter for stronger teams...
In my experience, match prep, short assessment of opp. weakness and your own weakness will give you better results. I've never been a fan of plug and play tactics. If you have a basic understanding of tactic you can have more consistency when you take these things in consideration, and actually...