I did a test with 2 voxel art tools, MagicaVoxel and VoxEdit, and both give me 2 completely different objects with their textures for a simple crate with some details
Around 400 vertex
A texture of 256x1 (exports the color palette as texture)
Around 250 vertex
A common texture where every face is drawn with it's texture
The thing here is that MagicaVoxel generates a few more vertex, but the texture is shared by all the objects who uses the same palette, so in the end, if I have 100 different models, all of them will share 1 texture of 256x1 pixels which is a ridiculous size
The question is, for performance, which is better? Have more vertex in your models but having only 1 small texture for all of them, or have less vertex and a texture atlas for all of them (which will end in a bigger file probably of 2048x2048)?