Individual not group competition
This is related to no free enterprise, but is more of a foundational concept. Individuals competing against each other for prestige is healthy and productive as long as that competition is within an umbrella of the one group.
This is much like in a tribe individuals competing against each other, but everyone working for the good of the tribe.
However, when you have two tribes competing against each other this is when it becomes inefficient because each spends resources in competition. The best solution is if both tribes merge into the one tribe and no longer need to compete.