i agree with martok, Africa is rich enough but the real advantage lies with your cavalry, africa is mostly wide open spaces and the numidians and carthaginians are too stupid to exploit it. build up good stacks of all cavalry (for speed) and blitzkreige any wandering armies, the southern factions have few spearmen so that is a plus. when you reach the north african cities they are far away so fitting in with the blitzkreig attack don't bring infantry, when you reach the city walls simply hire some mercs to use the ram, carthage if it still lives is most likely caught in war with the romans so by hitting there african power base your essentially killing them. but be warned this will empower the romans so retain peace until you have a ready navy and good stacks, force your way into sicily then.
ok, hope this is a good strategy for you, worked for me but i hav'nt played RTW for almost a year now (MTW2 instead) best of luck. (btw it will take a while for rome to fully enact the reforms so tke unwanted units and do suicide attacks on roman provinces to keep them cordoned off.
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