//радиус внутри которого считывается плотность огня (у меня так для удобства, можно зашить в код)
denRadius = 30;

{
     {
         _ehIndex = _x addEventHandler ["Fired", {
             _this  spawn {
                 private ["_last_pos"];

                 _unit = _this select 0;
                 _bullet = _this select 6;
                  
                 //высчитывается позиция пули
                 while{(getPosATL _bullet) select 0 > 0}do{_last_pos = getPosATL _bullet; sleep 0.01};
                  
                 //проходя по всем юнитам увеличивается счетчик если надо
                 {
                     {
                         if(_x distance _last_pos <= denRadius)then{
                             if(isNil {_x getVariable "densityFire"})then{_x setVariable ["densityFire", 0]};
                             _x setVariable ["densityFire", (_x getVariable "densityFire") + 1];
                         };
                     } foreach units _x;
                 } foreach allGroups;
             };
         }];
     } foreach (units _x);
}foreach allGroups;

getRelativePos = {
  /*
  Description:
  Return position at _distance and _position of the incoming _azimuth.
  If argument _direction is specified, the position will be relative to the _direction
  Syntax:
  [position, azimut, distance, (direction)] call getRelativePos
   position: array
   azimut: number
   distance: number
   direction: number (optional)
  Return: array
  */
  private ["_position", "_azimut", "_distance", "_direction"];
   
  _position = _this select 0;
  _azimut = _this select 1;
  _distance = _this select 2;
   
  if(!isNil {_this select 3})then{_azimut = _azimut + (_this select 3)};

  [(_position select 0)+_distance * sin(_azimut),(_position select 1)+_distance * cos(_azimut), _position select 2]
};

_pos = [getPos _enemy, getDir _enemy, _enemy distance _leaderGroup, -90]