Well, it depends on how much expensive it is in my opinion.
Of course the percentage can be adjusted, and the blacksmith doesn’t have to be included (even though it doesn’t have that big of an impact)
But no, I don’t think that it would be OP. The civ doesn’t have cheaper ships or siege, and doesn’t have faster gathering wood or such eco bonus.
The bonus just make them reach their mass of units faster, but it doesn’t allow them to outnumber the enemy. That’s the idea at least.
Besides, the main idea is that venetians can’t do a lot of things (terrible cav, no CA, pretty bad monks and just decent siege) so that few units that they have are good.
Close the Italians… yes and no… there were actually a lot of differences on a lot of aspects, that I won’t list since I already indicated them on several post in this thread.
As for the territory, well I don’t know its area, it wasn’t big for sure, but I think it’s comparable to the sicilians, or burgundians for example. I mean, besides their lagoon, they controlled Crete, Cyprus, Eubea several Greek Islands, the Peloponnese, the Dalmatian coast and islands, the Istria peninsula, and later on about half of the north Italy.
They weren’t the franks or the Chinese for sure, but they weren’t neither a nobody.
Could be, there are some images on the earlier posts in this thread if you are interested.
The goths are kind of a stretch for the Italians… yeah they governed the peninsula for some time, but had a little impact on the long term…
The longobards, which are the Italians in game, on the other hand had more of an impact on the history of the Italians, but the venetians were never conquered by them, nor by the franks or HRE.
So, if you have to find a civ to represent them, byzantine are the closest thing… but they are as close as would be for the vikings to represent the sicilians…