The Iron Age is named after the period during which Iron became commonly smelted and extensively used. The name has zero to do with Daniel. It became long before Rome became a period probably beginning with the Hittites as a major force in world history.
Sorry, that is not wher it came from.
It came from when certain nations ruled in power and the time periods from then
And that came from Daniel
Iron is older than than those time periods in history, but wwe dont call those earlier periods the IRON age, nor do we change Bronze or Iron around in those time periods when they were used at the same time.