Originally Posted by
nvm
It's actually pretty straightforward. Free City is a "weaker" allied government which allows family members to govern the province at the cost of being super limited in construction options, and only one time recruitment. It's not very practical unless you like to roleplay still build it in provinces like Liguria, the unrest there is so crazy high that the 5 extra happiness percentage and ability to be governed by FM makes all the difference, it's literally not possible to hold it as a client state.
Province is your ultimate government for anything outside Italy, but it offers no recruitment until Marian Era. So yeah. Your only option for any REAL recruitment outside Italy is either an Allied State or mercenaries.
As for which government is the best in Italy - you can keep Ius Latinorum for as long as you want as it offers you access to unique units which you would otherwise lose moving to a higher government tier. You can gain roman recruitment by constructing colonies within Italy, and that's the only place you can build actual colonies in until Marian reforms. Personally I prefer to build Ius Latinorum to an Allie State in Rhegium and Tarentum, as they too are less rebellious with a FM governing them than as a client state. Plus, the recruitment doesn't differ that much.