As Kitbag said the wheel track is only part of the story, the other very important bit is where the legs are attached.
To appreciate this imagine two aircraft with the SAME wheel track but on one the legs hang staight down (like Hurricane) and the other has the legs pointing inwards (like Spitfire) BUT in the inwards case the legs point so far inwards that they meet on the centreline.
Now imagine you are travelling over bumpy ground and one leg hits a bump. In the case of the H the aircraft upward force would change its bank angle a lot. In the case of the S the upward movement would be applied at the centre line with clearly different results.
Any help?