Well, I joined in ‘87, and have been hopping in and out since, so I‘m a little rusty as to how it used to be. Tactics had just been revised as I joined - our section attack handouts were very exciting to us because it was all in terms of C7/C8/C9, and the new weapons were only about two or so years out of our hands.
The biggest difference in section tactics with the new weapons was the elimination of certain groupings and formations. Keep in mind the FNC1 was semi-auto w/ a 20 rnd mag, and the C2 (a heavy barrel version of the C1) was capable of full auto, but had only a 30 rnd mag and a no-change barrel, so sustained fire was not really present. One option used by the section commander was the formation of a ‘LMG Group", putting your C2‘s together for fire spt during the attack. With the C7 capable of repetition fire, and the C9 capable of laying down a heavy volume of fire using 200 rnd box mags, the ‘LMG Group‘ isn‘t taught anymore, and the heavier firepower is spread equally throughout the section. Certainly the volume of fire put down by a section today is substantially higher than it was with the C1/C2 armed section.
I would say that accurate aimed fire was emphasized more then than it is now - I think that the temptation to blast off the rounds hastily is high because of the automatic capablility of the C7, and also because the C7 doesn‘t kick like a mule - somehow, that characteristic made you take a little more care.
The SMG was usually the radioman‘s,driver‘s, or NCO‘s weapon, and being a 9mm, there was not much range. It was prone to jamming, and was difficult to keep clean, as it fired from an open action.
I hope that holds some of the info you‘re looking for.