To illustrate ash's point about a "well-built team": imagine a hypothetical lineup of Steph Curry, Brent Barry, Donyell Marshall, Dennis Rodman, and Shaq. There's 1433 3PA, and hitting at a 42% clip (602 3PM). This would suggest it would be a good idea to go + on defense. But are you really going to cheat off of Shaq?
Obviously that roster is too expensive for an open league, and nobody in their right minds would play that Rodman at PF, but that's just an example.