The Nelson class's three forward turrets

What was the theory behind Nelson and Rodney's three forward turrets, and why is the B-over-A-and-C layout controversial?

The arrangement saved armored length, but its particular superfiring geometry was less clean than the F3 alternative.

The theoretical advantage of the Nelson arrangement was to place the magazines and main battery inside a shorter armoured length, allowing thicker protection within treaty displacement. The weakness was the decision to make B turret superfiring while A and C remained at deck level. The F3 arrangement instead let the rearmost forward turret fire over the two ahead. This separates the broad all-forward concept from the specific geometry chosen for Nelson and Rodney.