>>268690661
yeah, absolute modularity like you're depicting there would lead to development hell and more than likely an unworthy load of work 
I was more thinking of grabbing entire legs and brains and hearts or whatever and different kinds of abominations would require different parts in different quantities, because that would be 'easy' enough and the AI wouldn't have to adjust depending on whatever the fuck kind of monster you'd be making

though spore is an example of it being feasible, the problem being that spore's system took fucking years to be put in place, there's a reason we basically never saw anyone else try to do it

also depending on how deep you want the gameplay to be for each class/profession/whatever, you could have different qualities to the body parts of different kinds of people
for example a warrior's heart or arms, a sorcerer's brain, a maiden's soul etc to force the player to look around to find the pieces they need, instead of just butchering the first bandit camp they could find

>>268689950
that sounds way too fucking fiddly, but rather; having to use a dagger to cut it off from their belts with one hand and not before making sure to hold it with the other, else it would fall down and alert them
the precision required would depend on the level of the npc or something along those lines 

>>268690678
that's a given and I'm still mad it's not a thing in skyrimVR
[spoiler]hopefully this'll be modded soon/someday[/spoiler]