Yeah, you forgot the nonplayable tag. To unlock all the factions do this:
Code:
playable
	romans_julii
	romans_brutii
	romans_scipii
	egypt
	seleucid
	carthage
	parthia
	gauls
	germans
	britons
	greek_cities
	romans_senate
	macedon
	pontus
	armenia
	dacia
	scythia
	spain
	thrace
	numidia
end
unlockable
end
nonplayable
	slave
end