[Rules] LOS and OOP. Any interactions?

[triangular_cube]

Simple question (or maybe not). On the Matanikau map, can a unit in hex 1413 spot a unit in hex 1315 and vice versa? If so, could they do it through both 1414 and 1314? All intervening hexes are present (sort of) and terrain appears to be clear except for the Edson's Ridge map. 

I feel like scenario designers purposely try to avoid situations like this but JF#4 embraces it for no particularly good reason.