These have their own pros and cons, and may requires knowledge of character blueprint, but you have a few choices that does not requires re-do UVs(texturing).
-
merge only skeleton and animations, then use Modular Characters system. I am not 100% sure about your skeleton hierarchy and complexity, but your riggings seems relatively simple. therfore you just need a single root bone which has body and limbs as direct children. just beware any children of the Master Bone has to be a subset with the exact matching structure(arms need to be re-exported including root of body).
-
having many skeletons or separated parts might be later headaches - one example is bad performance. if you don’t need changing parts, combine bones and meshes then assign separated materials refer Multiple Materials. combined mesh requires re-do Skin/Weight job but it would be not a big deal since your character is rigid.
-
create arm sockets on the body skeletal mesh, then attach arms skeletal meshes to the body as form of child actors blueprint or skeletal mesh components.
because each parts will use its own animation sequences, you may have some problems when the synchronization of animations is critical.
- you may build relatively complex animation blueprint,
- or you will have to prepare animations that has same unit length
(sync animations manually), - or look for right looping frame lengths of common multiple.
i.e. 120 frames for the body and 60 for the arms.
good luck!