The “base” skeleton is very similar to Manny, but you have 5 spine joints instead of 3.
The main difference are the corrective joints on the torso, shoulders, elbows, hands, fingers, thigh, calfs and feet…and also the hundreds of joints on the face rig.
You can just download a MetaHuman, select the body ( or whatever other SK you want ), then open the SK and open its skeleton, and you’ll see the entire structure.