The muzzle-blast problem in triple turrets

Could close barrel spacing make a triple turret inaccurate?

Yes. Blast interference and shell dispersion were real design concerns, and staggered firing was one way navies sought to reduce them.

The exchange identifies barrel spacing as a cost and hull-size issue as well as a consequence of adding a third gun. Preserving twin-turret spacing would demand a wider mounting, a larger barbette, more internal protection, and potentially a larger ship. Bringing the barrels closer together risks muzzle-blast interference and poor shell dispersion, problems the Royal Navy had already considered while developing multi-gun secondary mounts. Wartime triple 4-inch mountings and later Town-class cruiser turrets show continued British interest in making multi-gun arrangements work. The cited American solution of firing the guns fractions of a second apart shows how a compact triple mounting could require a new firing circuit and different turret practice.