10 allies are not enough for diplo, this is not what I mean. You need to take 2 additional policies instead of something else. After the opener, consulates early game is very useful, especially with Greece, so you basicly need to invest two more.
The 25% bonus applies mostly in the very late game, as you need a lot of time to create these allies. So you have to skip something, so you invest there. What do u skip?
Rationalism? No
Order at least until LVL2? No
If you have so much spare culture, so you take this policy, you should already be far enough ahead, so you are gonna win SV regardless ...
Cultivating CS relationships as Greece is so easy you barely need to lift a finger. You don't even need consulates.
Rationalism doesn't give as much science as Scholasticism. You are killing two birds with one stone with CS alliances. 25% applies at any time. Deity CSes have huge science.