I'm playing Macedon, and I got the +4 Era Score for building a Hetairoi, but not for later building a Hypaspist.
In the Civilopedia, under Major Moments, item Unique Unit Marches: "You have trained this unit for the first time, giving you an edge on the battlefield."
It doesn't say first unique unit, or first special unit, only "this unit for the first time." So either the documentation is inaccurate, or the game isn't implementing what's documented.
Save game available on request, although this should be easy to check out.
In the Civilopedia, under Major Moments, item Unique Unit Marches: "You have trained this unit for the first time, giving you an edge on the battlefield."
It doesn't say first unique unit, or first special unit, only "this unit for the first time." So either the documentation is inaccurate, or the game isn't implementing what's documented.
Save game available on request, although this should be easy to check out.