Town-class superstructures balanced space and streamlining

Why did Town-class cruisers have different flat-fronted and curved superstructures?

The designs traded additional internal and flagship space against attempts at smoother airflow and speed.

The class's varying superstructures were deliberate design experiments rather than arbitrary styling. A flatter front made more internal room and could support a flagship role with additional command facilities. Curved forms were associated with attempts to reduce air resistance and improve speed. Ships within one class could therefore be adjusted for different operational priorities.