Why quadruple 6-inch turrets were more workable than heavy quads

Would quadruple turrets have made a proposed sixteen-gun super-Town cruiser unreliable?

They posed difficulties, but a 6-inch quad was much more feasible than quadruple 14-, 15-, 16-, or 18-inch mounts.

Not every quadruple turret posed the same engineering problem. Six-inch shells were light enough to place less demand on the mechanical handling system than battleship ammunition. That made a quadruple 6-inch mounting difficult but potentially workable, with even an 8-inch quad still more plausible than a heavy-gun equivalent. Above that scale, shock, weight, loading machinery, and crowding accumulated rapidly and undermined reliability.