As big as Steve Nash's impact on the Lakers might be, it can't possibly match the impact that flashy point guard Kevin Sheppard had in 2008 on A.S. Shiraz, a professional basketball team in Iran's Super League.
Our enjoyment of a film depends on our ability to suspend disbelief. Sports movies based on true stories are at a severe disadvantage in this regard. Many of us are acutely aware of every last detail of a sports film. Sports fans are conditioned that way. It's in our DNA.