What a larger 1910 Town-class cruiser would gain

If the 1910 Town-class subclasses were enlarged into roughly the 5,000- to 6,000-ton range, with 25.5 to 26 knots and a slightly larger Adelaide, would they be more capable?

Yes; the additional displacement would likely support more guns and make twin or turreted mountings more plausible.

The larger subclasses are judged likely to be more capable. Their additional displacement could support more guns and make twin mounts or turreted arrangements more plausible. The hypothetical retains speeds of about 25.5 to 26 knots and gives Adelaide a little more size. No detailed alternative armament layout is calculated.