Why the Gloucester group carried larger crews

Why did the Gloucester subclass have a noticeably larger complement than the other Town groups?

Its tighter machinery spaces needed more operators, and its East Indies role also called for larger embarked military detachments.

The Gloucester group's higher rated power came with more confined machinery spaces that demanded additional engine-room personnel. These cruisers also carried larger Royal Marine or soldier detachments for East Indies presence and policing duties. Spread across three watches, the apparent increase represented a much smaller number of extra people on duty at any one time. The complement therefore reflected machinery arrangement and overseas employment rather than a simple loss of efficiency.