Don’t bring a knife to a gun fight, unless of course your merc knows how to use it. Hand-to-hand combat is not advisable in most situations, but there are several mercs with the speed, stealth, and skill to be lethal without guns.
Running in for a melee attack can be a last resort if you are out of ammo, but it’s usually a deadly decision. Leave the striking and edged combat to those who are masters of melee abilities. Even these tough mercs are better off using a gun from any considerable distance.
Still, there are several situations where these mercs can get physical. Their first opportunity is in close-quarters combat (CQC) such as inside buildings. As long as they aren’t running around in a long hallway, they can use the corners and walls to get in close enough to be effective.
Another good use for their skill is to ambush a patrolling guard as they round a corner. Their physical skill should allow them to disable the guard quickly and effectively without making too much noise. If the merc has enough stealth and blending abilities, he can sneak in for a silent assassination.
Perhaps the most useful time to deploy CQC is on melee enemies that charge your squad. Let your shooters deal with the ranged foes and allow your melee masters to take out anyone foolish enough to get too close. It’s also important to keep in mind that melee fighters are deadly up close because their opposition is ineffective using a gun as a blunt object.
This works in favor of your melee merc, but it can also be used against you. Look out for crazed enemies charging at you with an axe. If they get too close, your expensive high-powered gun will be somewhat useless as they literally cut you down. Make sure to fight fire with fire and assign your skilled melee mercs to contend with the charging melee attackers.