@Redmattgame the only confusion so far for me (after miles_occulision command was made redundant) has been teammates walking behind me but that is actually a teamwork issue, in my opinion, = people like to just follow you closely for whatever reason that is even though it makes you easily noticable, easy to hit all with one granade etc.
And even that should not hinder (much) of your performance as you should be aware where the enemy team is and can they somehow be behind you.
Otherwise, if this is the 3rd party - back to my point about chaos in battlefield situations.
To be 100% where enemies are you have bloodhound and seer and crypto (yeah actually some people still play him :D).
Sure it would be great to have a sense if someone is coming from behind yet we have directional hearing and even if the sounds of the enemies would be there they would be dampened / lost in all the firing noises and sound coming from the direction we are looking at = useless or close to that.