How an expanded Tribal class might be named

If the Royal Navy continued building Tribal-class destroyers in the gas-turbine counterfactual, would it use names from ancient British peoples?

Possibly later, but it would probably continue using names from peoples across the empire first.

The Tribal-class naming scheme was intended to give peoples across the British Empire ships that represented them. Ashanti, Gurkha, and Maori are cited as examples of the connections those names could create. An extended programme might eventually use Brittonic, Iceni, or Pictish names. The expectation is that the Admiralty would first continue drawing on peoples across the empire.