Alright, I’ve figured out how to pull this off. Huge thank you @Evgeni_Popov.
updating this post incase anyone ends up here trying to figure out the same thing.
I’ve brought my mesh into blender, parented the mesh to the existing skeleton for the character:
(select the mesh & skeleton > CTRL P > Armature Deform with automatic weights.
You can bypass the multiple skeleton situation previously mentioned by disposing the new one after importing the armor model.
here’s the PG: where we finally got things working (hacky, but functional.)
https://www.babylonjs-playground.com/#AHQEIB#215