Use Briton buildings and Iberian units?

Only issue is what civ to represent it Lusitanians were a different culture from non-indoeuropean Iberians and current Iberian civ is some Iberian/Lusitanian/Tartessian/Celtiberian hybrid. There is a mod with Lusitanians though.

Millenials were insulting each other on Xbox Live think it may just be a case of the game being less popular (or at least with that sort of audience) back in the day.

I dont think every generation is an exact copy of previous ones. So se some generations will be worse than others and in some cases it might be right (not the case regarding players of this game IMO).  

Many years ago it wasn't like that, Stan once subtly hinted to me: "those people weren't even born back then".   Now I understand what he meant.