Is it possible for a dead NPC to be positioned in a death way other than what the game introduced, such as the dead body slouches back? I see through the work of bethesda when it comes to certain dead bodies, that they made them throughout the game where they're positioned in a specific way, such as one near the fallen log where Lost Knife Hideout is at. Am I able to do that or no?

They have havok turned on when they do it. It's very had to position them still. For very specific positions not possible through havok alone, they use a node called "RigidBodyDummy" and attaches a corpse to it via AddHavokBallAndSocketConstraint()

In the CK's main tool bar, click on the button that says "HK" this will turn on havok, and cause everything that isn't checked "Don't Havok settle" to fall.

Make sure the first two red buttons are turned off, as it makes positioning them a little easier.

An example of the node and the script function in action can be found in GallowsRock01(interior). Go to the jail cell containing what appears to be a distorted wolf(this is normal) IIRC click on him or the orange boxs to look at the script.