Every mine has its different economics, think I read that MGX have a strip ratio around 7:1 at Koolan island but they have excellent grade and no rail costs to worry about.
Most hematite producers would have a strip ratio in the 1:1 to 3:1 range, but grades will impact the profitability.
Railway's 1:1 ratio is a real plus, lower mobile equipment, diesel, tyre costs. More profit!