Hi Guda,
My python script will look like below if it's me to deal with the problem.
row_poly=arcpy.SearchCursor('mypolygon')
row_poly.reset()
row_s=row_poly.next()
while row_s:
feat=row_s.shape
... # x,y=feat.x, feat.y , find all the x, y coordinates of every polygon
x0s=min(x) # the leftmost x coordinates, can be many points
y0=max( y for x=x0s) ? # it depends on your difinition of start point
array_new=... # reorder your point array with the x0,y0 be the first point
... #delete old polygon
row_s.shape=polygon(array_new,...)
...
row_s=row.poly.next()
But I don't know whether it's the best solution.