I do this regularly and not only with EB, but with other mods, and always worked much better.
Even that change is far from real life, as in real life rout and crumbling would start after 10-15% casualty rate even faced frontally only (not to tell charged from behind which only best hard core veterans would stand). Most of the casualties were during the rout, not during the combat.... Levies (especially skirmishes/arches/slingers who even stand in prolong malee in game..) would run even on sight of charging cavalry or seeing professional unit coming on them, even before real contact...
I have mentioned it once but EB team was deeply against it...for some reason...