Right, now I've used Caligula to "Make a new unit" of the three units I wanted. I used each original merc unit as a base, and (in Caligula) simply removed the chevron from "Mercenary Unit". Then I renamed the "new" versions of Illyrian Merc, Cretan Archers and Rhodian Slingers using "greek_" instead of "merc_" as a prefix. Well, whaddya know, they still don't show up in-game..

I don't understand what I'm doing wrong here. I've added the hidden_resources (kreta, illyria and rhodos) for the 4 cities I wanted (listed in my first post), I've added the names for all factions supposed to be able to recruit the units (=all factions with greek culture +"egypt"/ptolemaids), and added the units to the unit build lists in buildings_desc.txt, where I also added the "..and resource xxxxx" after each unit respectively.

Anybody able to help this poor, bewildered newb?

Please do PM me if you're able to make a good step-by-step "walkthrough" for accomplishing what I've explained in my posts.