Oh I dunno, Chris. I wouldn't underestimate how much tactical knowledge people who skirmish regularly have picked up from all kinds of sources, or how much experience they have of making what they know work during a skirmish, even if that is, like me, just one really good tactic that always makes sense, so I've rinsed it. The main problem I see in the field is that we are often unable to quickly explain our ideas, or even what's actually going on, to each other quickly enough because we do not have a common succinct vocabulary.
When it gets to the whites of the eyes stage, when there's literally nothing but movement and firepower between you and a hand in the air, who can deal with "Uh, yeah target to your right, sort of two thirty-ish. He's moving round. Like, you know, to your right. Further right I mean. Yeah, there's another one over there somewhere as well. Where the other one is going. I think. That's where he was when I saw him last anyway. Er, three o'clock. Maybe three thirty. Behind the bush next to the bigger of those two trees. The bush on our side, on the right if you turn and look at it..."
"Target advancing right. That's two trying to enfilade us.", is much better but, unless you know that whomever you are speaking to knows what enfilade means, there's no point in saying it because it'd only take more thinking time to explain it. I swear, even just a little radio discipline like, with PMR446's to press the PTT and silently count "one banana" before you speak; to first identify yourself then say to whom you are talking; to think what you are going to say before you start talking so that you minimise the umming, ahing, uh, like, i mean, ya know, etc. all to increase intelligibility, would massively improve a team's chances, but combine that with a common syntax covering all basic situations and I believe the team's effectiveness would increase exponentially with every extra person 'online'.