Why HMS Caesar did not lead to a fleet of Roman emperors

Why did the Royal Navy use HMS Caesar but not individual Roman emperor names such as Tiberius or Trajan?

Caesar had become an established historic ship name, while Roman emperors never developed into a preferred naming theme.

HMS Caesar existed because the name had already accumulated a service history worth preserving. That continuity did not create a general policy of naming ships Tiberius, Trajan, or after other Roman emperors. The isolated Roman example contrasts with the Royal Navy's greater comfort using names drawn from Greek gods. Precedent can therefore sustain one name without establishing a whole thematic class.