Brutus Forci,
Wharves send fish directly to granaries.
patrician,
For full production, a cart pusher must return to its building by the time the next load is produced. For a wharf at full production, the maximum distance to its granary depends on the distance to the fishing grounds. (The closer the fish, the higher the production and the closer the granary should be.) If you put housing blocks far inland in Massilia (I didn't), it may be best to put "accepting" granaries near the wharves and "getting" granaries near the housing.
paultheo,
The idea of using a combination of luxury housing and fairly poor housing is about as old as the game itself. Marty Party's Massilia used luxury palaces and tents!