NPCs can 'learn' to protect from excessive leg or head shots.
Like for instance arrows are much more lethal, only a few swings will kill me and enemy etc. To clarify, simple and effective means people die in 3-4 good hits, depending on their armor rating, and sneak attacks can almost one shot people. The mod adds hundreds of new magical abilities to Oblivion, along with new mounts, and even transformation powers. It features 4 guns, which extend when armed. Oblivion combat mod 29 to be able to bob and weave.