Its more the spread of the inner races that are part of the loose ball type spindle ..

BITD Campag had 2 different thicknesses of cups *, the thicker one was Spiral impressed to have particles be ejected as the cranks Turned.
in both the BB set sold to builders in Italy and England.. so bearing race was wider or narrower spread on their various axles ..

*between the outer cup race and the outside Face of the part.