Could we possibly make it compatible to 0.28? Or should lilypoppy's mod only apply to the next release 0.29? (which will be released sometime next year anyway, I hope)

I could not find any evidence for clubs.  The warbands themselves are mainly attested in early medieval legal and mythological texts. Some of those stories are set in the 2nd or 3rd century but that does not necessarily mean the Fianna existed back then (although they migh be from a common earlier Celtic/Indo-European tradition). In any case the main weapons in the epics are spears and occasionally swords. A similar unit for the coastal fort could be a sort of Caledonian mercenary since they appear to have had ties to Ireland . They would have tattoos and fight with swords and small shields. https://europabarbarorum.fandom.com/wiki/Colgacilioi_(Caledonian_Swordsmen)

I agree that I find this complex. And once I have my scenarios, how will it work?

Not sure at all if this map is using an equal area or isogonic projection For sure it aims at "iso-balancing". 

@lilypoppy is right - let's stop argueing and make the game a bit better every day (in differnt ways, software, maps, historical accuracy, voices, music, artwork, mods, whatever). We all do know that there are still miles to go if we arrive ever. As an engineer I dare stating that a product you ran out of improvement ideas for is essentially dead.