This is completely subjective. How is anyone supposed to give a map sprite a dismounted “energy”? What makes an infantry unit look more like a classic infantry unit than a dismounted one?
They were done with the intention of being used as dismounted units, therefore they should be put in the same folder as them for easy accessibility. Putting them in the “normal infantry” one because YOU personally don’t “get it” would just make it harder to find them when needed. People may not even realize those are an option if you do that.