Crown Colony cruisers as wartime Towns

Would Crown Colony cruisers still be attractive if Towns carried fifteen 6-inch guns?

Yes. They would be useful quicker-to-build wartime versions of the same broad cruiser concept.

The Royal Navy needed cruisers that could be produced quickly as war approached and then began. The Crown Colony design retained much of the Town class's speed, armor and 6-inch capability while reducing the demands of construction. Even if a Town carried fifteen guns, surrendering three of them would be a reasonable exchange for getting more hulls into service sooner. The comparison with the American transition from Brooklyn to Cleveland shows that this is a practical wartime derivative rather than simply an inferior cruiser. Production speed becomes a combat characteristic in its own right.