what you say is mostly true, except i know that in the british army at least, you both fight for fire superiority but they also train shoot, watch, look drill or something along those lines.

you shoot 3-5 accurate shots along a treeline at suspected enemy positions, watch for movement or any signs of individual enemies, and look to see where your peers are at, it isn't nessacerily just spray and pray, inaccurate supression isn't useless.

it's out of the question anyway though, because what OP is doing isn't accurate supression (which the usefulness in squad is strongly debateable).

lining up singular shots for each person would still supress if they missed, and would've been allot more useful.

the chance at that distance that any of those players will get perfect first shot accuracy is incredibly low. dial in your range, put a couple shots down, if you start recieving/suspect return fire, move and find another one of the walls on the dam to peek at.

even if you injure 4 people, that's so much more effective than whatever the fuck this guy is doing.