WRT weakened or badly overmatched platoons holding up advances because they're hunkered down in town hexes, many MANY years ago someone published an optional rule on AP's site that added some sort of morale penalty if the defenders were completely surrounded by the attackers. To my memory it was well-designed and I liked the concept quite a bit, though not well enough to be able to remember enough details to link you.
Maybe someone here with better brains can understand the document I'm talking about and find it. As I recall it elegantly solved the invulnerable speedbump platoon problem.
