Team performance v. Player Ratings

Are teams performances due to anything other than player ratings? Or are there some team ratings or team home and away numbers somewhere that effect performance. The reason I ask it I'm running an All-Time Greats League and teams that have no business winning are winning at a fairly high %.

Coach Profiles/sliders also have something to do with it.

how about team chemistry? I noticed when I force trade a lot of players so that my rivals are more talented, they still dont win enough games esp when team chemistry is low.

That too. Forgot the specifics (player ratings? coach sliders?) on what is affected when team chemistry is low.