Blues or Morales as long as you re winning you won t need to farm, and they are useless anyway.
Reds or Treatments as long as you re growing your stadium facilities you should receive couple every day and if you re watching the game and not getting a card you also get one, so you Don t need to farm that too.
The 8 players beside the Fast Trainers attackers I talked about can be 4-5* players you will sell at the end of the season, if you have more money you can keep more fast trainers, but 3-4 is the max I would do personally.you can keep them 7-8* every season with ease.
I have a friend who uses this tactic and she wins everything.
Have a guy I helped having a blast of a season right now.
The main player , preferably AML-AMR should have the highest rating of them all and I would train him free kick Special Ability and use him at penalties,free kicks and corners.
That concludes the most important things I think.