Common designs and Suez logistics in a fictional British Empire

How might naval design and logistics work in a fictional Empire where the Sirens prevent decolonisation?

Use British parent designs with locally built variants, while standardising weapons and support around the Suez lifeline between the empire's main theatres.

The question places a continuing British Empire in a fictional scenario involving Sirens. Canada and Australia could develop local variants of Royal Navy designs, with Australian Leanders offered as the historical analogy. New Zealand and South Africa might receive some locally adapted ships too. India's position is left less certain because of the fictional Sakura presence in the region. Suez would become even more important as the empire's logistical lifeline. Standardising gun calibres and capabilities would help support the dispersed fleets. These are initial suggestions for the scenario, with a fuller answer requiring more detailed study.