Form factor means a warship's overall design shape rather than a single dimensional rule. Pre-dreadnought ships often carried guns at several levels and through many separate openings. As guns became larger and more powerful, a ship could carry fewer of them. Moving those weapons into turrets gave each gun a wider field of fire and extracted more value from the limited battery. The transition toward dreadnought layouts followed changes in the scale and employment of naval artillery.
Notable Point · 1:37:09-1:37:39
How larger guns changed the form of warships
A quick design explanation traces the shift from multi-level gun batteries to turrets as guns became larger, fewer, and more valuable.