Once you defeat the starting ships, the AI don't often build anymore. The Ptolies do, but usually only if they don't control Antiocheia and of course do control Alexandreia.
I sometimes roleplay Eleutheroi fleets as fleets of Carthage or whatever.
Still, I think the mass spamming of ships in RTW Vanilla by every nation with a port was a bit too much. However, I do wish there were more ships. Still, this will all be sorted by EB III, when we can fight on water properly

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