A Euhemerist reading of the widespread Heracles cult was attributed to
a historical figure who had been offered cult status after his death.
Thus Eusebius, Preparation of the Gospel (10.12), reported that
Clement could offer historical dates for Hercules as a king in Argos:
"from the reign of Hercules in Argos to the deification of Hercules
himself and of Asclepius there are comprised thirty-eight years,
according to Apollodorus the chronicler: and from that point to the
deification of Castor and Pollux fifty-three years: and somewhere
about this time was the capture of Troy."
Readers with a literalist bent, following Clement's reasoning, have
asserted from this remark that, since Heracles ruled over Tiryns in
Argos at the same time that Eurystheus ruled over Mycenae, and since
at about this time Linus was Heracles' teacher, one can conclude,
based on Jerome's date—in his universal history, his Chronicon—given
to Linus' notoriety in teaching Heracles in 1264 BCE, that Heracles'
death and deification occurred 38 years later, in approximately 1226
As to the town names, the name Herakles (Pride of Hera) is still in use as a first name in many European languages influenced by either Greek or Latin:
Naming places after people has been a common practice throughout history. It stands to reason not all Herakles-named places originate from a singular person, mythological or not.