I think this might be a breakdown in the reductionist model, Robbo. Everything you say is true, but to produce more reliable wins, communication is surely very important. I wouldn't rate it as most important- as you say, tight play and accuracy are the biggies.
Communication is a different kind of virtue from good technique. Technique is an individual virtue, something each player must develope to be a factor in winning. Unity of the team, whether by disciplined communication or long acquaintance is a sort of meta- quality. It seems to me that it is what distinguishes teams from collections of individuals.
The smaller the number of players to a side, the less important it seems to be, but as more players are added to a team, the more important spreading information becomes. Unseen moves contribute the majority of eliminations, no? Communication decreases the likelihood of moves by the opponent being dealt with.