Why very large multi-gun turrets are so difficult

How serious would gun interference and mechanical complexity be in a six-gun battleship turret?

The problems multiply sharply as more guns must work together, making an extreme multi-gun turret a punishing engineering choice.

The question invokes a six-gun turret of the kind associated with the Tillman proposals. Each additional gun brings its own mechanisms and interactions with the others. An illustrative sequence assigns three sets of problems to two guns, six to three, and about ten to four. These figures are a heuristic for increasing complexity, rather than measured failure probabilities or a formal calculation for a six-gun turret. The point is that adding guns can make their combined installation disproportionately difficult.