Yeah, they won't be huge at the beginning. Our business is to make them grow huge quickly.
One thing we could do is boosting income and growth in the city of Genoa just like KK did for all other capitals.
Also nice barracks could help their early conquest. They would probably hit Florence first, then Ajaccio and Marseille following with Bern and Milan. After that they can land in Palma like Milan does now and meddle into french affairs. This is how I imagine their potential progress.
I doubt we will ever force them to take Antioch, Caffa, Iraklion and so on... Colonies aren't working good in M2TW anyway. But at least we can have a strong competitor for Venice, France and HRE.