How do I do it?
I know that one can edit the factions in RTW in C:\...\Rome - Total War\Data\world\maps\campaign\imperial_campaign\descr_strat.txt, but what about BI?
C:\...\Rome - Total War\bi\Data\world\maps\campaign\barbarian_invasion\des cr_strat.txt,
Changing the playable factions works the same in BI as in RTW.

So obvious...
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