The front tire needs to lead the rear to pull the tractor for steerability. If reversed, the rears will push the front around and make steering very difficult. Ratio's I have seen are 4% lead on the front, meaning you would see slip marks in soft soil, where the front tread met the soil, and at the front side of the tire tread, and none on the rears. Don't ask me to calculate that for you.
If you see the slip marks on the rear of the front tread, the rears are pushing and you are on the wrong side of the equation.....my 2c.