Also, there's hevee's specific blender-jme route. Is more advanced in certain way than md3, as has not the uv seam problem, is based on blender,which is free, and...I guess...as is vertex animation...you could very well have a blender scene...import seprated meshes...asign to the armature bones...and go exporting -deleting the rest of parts(but keeping a copy of the master allways! you will load it every time, and import the parts there: I'd somehow tell the artist make sure the parts match at least more or less, in proportions at the joint area, etc(of course u can avoid by code that the fat guy arms has the weak torso...heh, could be funny))