How to merge actors without overlapping UVs?

I’ve been merging assets for a game and I’ve been getting upwards of 99% overlapping UV errors. When I look up how to deal with overlapping UVs, I find docs on changing the static meshes in Blender or Maya, which I’m not proficient with, or rebuilding UVs in the mesh, but I’m working with merged meshes and these options don’t appear or at least I’m not finding them. What is the best practice for this? Am I merging incorrectly? Thank you for your input and help!

I have same problem. Any idea?