Hello, in fightclass this option count target (it doesn't make sense but I won't change it to avoid breaking the existing fightclass)
Use this c# condition to don't count target:
ObjectManager.GetWoWUnitHostile().Count(u => u.Position.DistanceTo(ObjectManager.Target.Position) <= 10 && !u.IsMyTarget && u.IsAttackable) <= 3
replace 10 by the range, and 3 by number of unit