Which British light cruisers were the better missile-conversion candidates

If the British Empire had not declined, would Crown Colony and Bellona-subclass cruisers become missile cruisers, and would Sea Slug resemble the historical Mark 2?

Crown Colonies are considered likelier conversions, and Seaslug's form would depend on its development under the different budget.

Crown Colony-class cruisers are considered likelier conversion candidates than the Bellona-subclass Didos in this counterfactual. Concerns about the Didos are raised without a detailed explanation. A different imperial budget would also change the circumstances in which Seaslug was developed. Its resemblance to the historical Mark 2 therefore depends on what that programme produced.