Yes, I understand. Light infantry units do it that way also.

But the authors basic contention is that you need to start with big squads of 12 or 13 people for the fire team structure to hold up under attrition. Even if two teams in a smaller squad is better in theory the fire team structure will soon break down in smaller squads due to combat attrition.

Few Vietnam Army infantry vets remember their squads operating with fire teams very often, even though the two fire team structure was doctrine during that time. Ask them how many people they remember in a squad and you hear things like "five to seven," or "six to eight."

When that's reality does it matter if two teams are better in theory?

We've hashed this out pretty well on other threads.