Are you talking about the decision to let the AI call the plays during each game? Or are you taking about who sets the sliders in the team strategy page? Two very different questions.
If it's the first, I let the AI call the plays for me. It makes the game go faster and it removes any suspicion that I'm winning because I'm smarter than an AI (which is doubtful in my case
).
If it's the second, there is lots to learn about how those sliders work and what the effect is, so I won't get into it unless that really is the point.