Divisions block movement of non-allied divisions as before, except only
TO locations controlled by that division's city or its allies. So if
non-allied division A and division B are in the same spot, division A
will only prevent division B from moving to adjacent locations
controlled by division A or division A's allies.

-Varian

Penned by my hand on the 15th of Haernos, in the year 129 MA.