Use of the fire team is common doctrine in the US military. Typically constructed around a four-man team of Leader, Rifleman, Automatic Rifleman, and Assistant Automatic Rifleman. The fire team doctrine predicates movement around and for the Automatic Rifleman.
When the concept is broken down, the idea is to bring superior force to bear. That strategy is an effective one for fire superiority and for taking ground. When analyzed, there are a few weaknesses. If the Fire Team is not, in fact, a superior force, it is vulnerable. Also, a superior force can be defeated regularly by an inferior force that picks it's shots well, then moves away.
Like a boxer who only engages for brief exchanges, then skips out of harm's way, a fire team centered around superior marksmanship would have certain advantages over a team built around an automatic rifle.
Obviously, if either team set up a good ambush of its choosing, it would have a significant advantage over the other. However, due to the very nature of the marksmanship based team, there is an inherent advantage in its doctrine of constant ambush opportunity. The marksmanship team knows it's only advantage is the ambush at a distance, and only allows engagement in that criteria.
The Automatic Rifle team is prone to getting into firefights without as much regard for distance, as they feel the automatic weapon can help them fight their way out of it, should a need arise. It's this thinking that can get them overwhelmed, too.
For the American Martial Artist, marksmanship is key. Understand how to hit your target, be on the lookout for targets of opportunity as well as favorable engagement ranges and circumstances, and keep creating distance after engagement.
The marksmanship based fire team can also work from groups of four. But it can be worked easily with just one or two persons. A team of three just might be ideal. Four and five are fine. Six or more and you koneed to see if you can break apart into smaller units.
The marksmanship team needs to know CQB well. Be able to fight up close if needed (it will be needed at some time). But also keep in mind that distance is your friend. Engage and move away with much prejudice.