Is it possible, in a mod, to create the possibility for land units to be able to cross an all sea hexside from one land hex to another (as in the figure below)?
I'm not sure if adding a road will work, but the alternatives would be to change these to be land/sea hexes, or to have a LOOP script, presumably triggered by a Decision (a bit like for Axis naval units entering or leaving the Med in our WWII games).