Can I have different amount of elements in LODs

Hi everyone, I’m working on my first character in unreal, I managed to import everything till now, but I wanted to add a LOD1 mesh I had already prepared, the problem is that I made a quite simpler version of the character, so he has no eyes or eyebrows meshes(I simply projected them on the mesh of the LOD1’s body), since I thoght as long as the model share the same skeleton it would be ok, I actually tried to load the LOD1 in persona, using import LOD level1, but it says import Failed, so I checked the manual and grouped the elements in MAX, but some elements(the eyes and eyebrows) dont have a LOD1 version, I simply wanted to use less elements, but importing this way I noticed Unreal still keeps those models from the level0 to level1, and I don’t want them and there’s no option to delete or to say that those elements should not pop up in the LOD1.
So my question is, can I have less elements for different LODs, or should the number of elements always match?
And is there another way to import a LOD for a skeletal mesh, for example importing it as a different skeletal mesh that share the same skeleton, and say to unreal to just use that skeletal mesh as a LOD1?
Thanks in advance for your time.