You may have to elaborate this to get a more suited answer. Because six textures with six different UV maps (UDIM or not) with the same resolution.. of course will give you a higher pixel density.. or using one six times bigger image in the first place (?).
256fes Pathfinder from Apex Legends. a low-poly model I made in my free time. The model has only 256 triangles and 256x256 texture. I tried to change and reduce his design a bit to make it fit with low-poly style. It was fun and challenging painting on very low resolution texture. Model in Blender. Paint in 3DCoat and Photoshop. ArtStation - 256fes Pathfinder Fan art, Paphonsan Duangtasawat
I'll like to share with you a video tutorial that I just made on how to create hand painted textures for videogame weapons. In this case I wanted to replicate the art style of “Ruined King” based on the beautiful concept art from Baldi Konijn.
Knowing that this may have originated from HoTS gives the needed context IMHO - and I think this perfectly illustrates how something that may be relevant for a very specifc (and somewhat hacky) edge case is not to be taken as gospel, and can end up costing time and ressources.
I personally didn't take part in the development of HoTS but I can certainly imagine a rather unfortunate set of circumstances in which things need to "look cool" for review at the highpoly stage, yet ending up looking too weak once baked down and viewed at RTS distance. Of course such a situation is absurd since as pointed above by EQ this stuff should *obviously* be taken into account earlier up the pipe - but if the highpoly sculpts are considered throwaway assets and if everyone involved is fine with wasting time on such "double takes", heck, anything goes.
I still do believe that this is inherently absurd though, and a sign of a poorly optimised art pipeline and review process.