Birs city

The main purpose of these cities is sink OLU attacks without a good LS escort and sniping CS.
Very easy to be build, because you can start making birs with academy 13.

Best islands:
+stone and regular wood or + wood and regular stone

Building priorities

Senate 24, in this level you can pick the special constructions;
Academy 13 for Birs and 16 for Light Ships;
Farm Max;
Warehouse 20, to stock resources for building more ships;
Resources that one with + max, normal 35, - 30, this is for your  fleet basicly .
Market 10, to send unwanted resources to other cities;
Barracks 10~0, to farm with Horsemen, if not, get rid of it;
Harbor 30, if you use Call of the Ocean, then Harbor 25 is enough;
Temple 5;
Cave 10, it’s cheap and costs 10 of population;
Wall 25, it depends, but in the beginner is important to have a solid defense;
Resources that one with + max, normal 35, - 30, this is for your  fleet basicly .
Special building: Thermal Baths and Tower/Divine Statue(temple 12), more population and more defense or more favour.

Academy priorities

City guard, when you’re attacked, use your militia, with this research you have more “pop” defense;
Villagers Loyalty, only if you have a farming village in your island(don’t spend BP in Farm villages);
Ceramics, extra 2500 store of resources;
Architecture, you will economize many resources;
Trainer, to build your army faster;
Crane(good if you have the advisors and if you’re active);
Birremes
Plow, free farm level basically;
Phalanx, for a stronger defense(you call members of your division or send support from your cities);
Mathematics, for cheaper navy armies;
Battering ram, both for offense and defense;
Cartography, your naval attacks are faster.
Only upgrade your academy to 14/17 or higher if you have many resources.