When you look at a penalty prone team who do you look at? Do you need more disciplined players? Or coaches not preparing the team good enough or both?

I look at my 8-0 score and shrug.

:)

It all comes down to chance in the end... but to answer your question, yes. Discipline is tied to the chance the player commits a penalty. Coaching has little to do with penalties if any.

Also check your fatigue settings - more fatigued players are more likely to commit penalties.