Not going to check numbers or discuss the point, but what you have to realize that even small numbers might make a lot of difference. It's not about the raw damage small arm weapons can do, but moving the threshold of numbers of shot required to kill through AT sources.
It might not be the most frequent situation, but anything involving PTRS, HMG/MG upgrades, indirect fire and even nades, might make seemingly non consequential small arm fire lethal.
Indeed. Sometimes a light vehicle makes it out of a busy battlefield by literally a scratch, sometimes it doesn't. Sometimes a 5% chance for 8 damage happens, sometimes it doesn't.