Led by the Headman, Headhunters are Cobra's street level enforcers. They deal with the things that Cobra Commander wants nothing to do with, other then the profits, mainly illegal narcotics, firearms, grand theft auto, and kidnapping.
Their preferred method of enforcement is 12 gauge. Although nothing is out of the realm of possibility when it comes to getting what Cobra is owed. They are truly brutal foot soldiers.
The grenadiers are used when absolute destruction is called for. Usually only assigned one to a unit, they are able to take out most threats with a well shot grenade.