Well, in Nap/ACW/REN/EAW you have the big problem with routed units that can break 2nd line... i prefer dont have troops behind a weak line because in the end you have double units running to the wrong side
Maybe a rule that made in WWI title that routed units have a bonus when are in the same hex or adjacent hex of a friendly unit to recover Disrupted status... not only the divisional/brigade HQ can prevent these troops leave battle, an official is an official and a blockade for routed units work with rifles from any unit.
But i dont see easy break units in France14, they can eat a lot of damage.
A little question Volcanoman, you are going to use in WWI serie the fanatic nation rule from PzC engine??? maybe in some defensive units and elite units is interesting.
PD: main question for me is release by 100th aniversary or not