What a gem: Veteran gamers may well wish to adopt House Rules of this type for this situation, rather than use the simpler rules presented here.
Designer: "Gee, let's make rules for the most complicated game on the planet and then bury a more realistic rule as a suggested house rule only for Veteran players."
Why not just make it the rule? That's what Veteran players would well wish for, right?
It's not all that complicated to grasp, given the complexity of other mechanisms we are forced to deal with.
But, I can imagine it would a difficult rule to write, with a lot of odd cases to come up with regards to what constitutes LOS 'on the other side of the hill.'