by bravucon
Well, I was going to answer but the designer made it before, so not much to add... but I was going to say something similar.In the first turn, when I said "Prestige around 10" I exaggerated a little bit, I should say 6. But having 6 prestige points for the beggining of the second round let you a lot of margin to maneuver because it's not the same to have 4 prestige at the beggining than 6 with your hoplites and Polis established around the map, and Prestige shortage probably would not be a problem for the rest of the game.
How can you achieve that? My idea is (the order of the actions should not be taken strictly):
Let's suppose we are Athenai:
Collect taxes in Attika (you don't have to spend Prestige to do that) I guess you should take 6 silver as you start without this precious resource. This amount of silver let you provoke a Civil War with the Proxen in a Population 3 Polis (Samos, Thebai or even Argos nex to your opponent homeland), maybe the less interesting is Samos as you have already Chios in the same region and you can't collect taxes two times per round there. This get you 3 prestige.
Now, take out two hoplites from Thebai and send them to Naukpatos (-1 prestige) as you could besiege this Polis without throwing the dice. [But I would go for a more ambitious goal and prefer to go to Korkyra, Pydna or Poteidaia, you really have 75% of chances to get there (and win +1 prestige)] Let's continous supposing that you went to Naukpatos. Trying to siege there is compensated by the 1 prestige point you get when you take this Polis, so you have until this point a net balance of +2 prestige, you're at 6.
Now it's time to send your 3 hoplites of Attika to collect taxes to Boiotia (-2 prestige), later to Thessalia (-2 prestige) and your 2 hoplites in Ionia can collect taxes too (-1 prestige).
Wow! now we have fallen to Prestige 1. But it's time to trade with the merchant, and maybe make another merchant to trade one more time.
Now we should have a lot of food: 4(initial)+3+3=10.
Make another 3 hoplites from Athenai to avoid feeding them. Also you can make one galley in Athenai and another one in Chios. So you have all of your Polis (5) with one population cube... but remember that you have 10 units of wheat!
It's time to make some population growth in Chios (+2), Chalkis (+1), Naukpatos (+1) and, why not, Athenai (+1).
Megalopolis is going to provide 3 prestige points.
If you manage to make a Project you can have 2 or 3 of prestige more, if not, you probably would have enough silver to go with the Proxen to Korkyra, Pydna or Poteidaia and get another Polis providing you 2 prestige points.
I think this could be a realistic opening for one player.
In the case of Sparta they should go to Sikelia and take Gela with the Proxen early to get food without depending too much in the trade routes. (I guess if I'm the Spartan in a future game, I'd try to do this as a first main goal).
I don't know I have played Polis only once face-to-face but I'm thinking a lot about the strategies that each player can follow.