Oh, I do hate "statistical firefights". Unfortunately, the 20% of the time you need to reach out and touch someone, it'd be "nice" to do so with IWs.

I've done some "cow-patty" shooting at the 600-800 meter range, and was amazed at how easy it was, under certain conditions, to "ID" the target, and then, how relatively easy it was to hit the specific area IVO the target, as well as the target itself. (Cow patties give a relatively spectacular secondary effect, whether wet or dry.)

I was shooting an Ishapore in .308 at the time, with iron sights. The terrain was rolling, with the longest possible shot right at a mile. (No joy at hitting a target at that range, though I might've scared it, should it be a vehicle).

Bottom line, I think there is a place for both 5.56 and .308 rifles in a serious military's arsenal. Machineguns are relatively inflexible, compared to a rifle.