Penals are meant to fight at long range and LMGs aren't exactly accessible for them outside of special circumstance.
Rangers, not so much.
If 3 bar rangers were anything more then a factual possibility, they would actually be used this way and I have never seen them used that way outside of vacuum tests.
Actually Penals can fight in most ranges since their weapons are good at all ranges.
The fact remains that according to this test they rank 4 as the long range unit above units like LMG paras.
Your theory that because you have not seen something it is not good, has simply gone out the window, when you insisted that Dshk was crap and needed a buff for years (because no one used it), only to be proven completely wrong when it dominated the meta for several months before they had to nerf it.
Have nice day bb.