That might be the case, but this is before it is even possible for the AI to found a government. I don't have the Babylon DLC so it's not that.
I don't think the AI could've gotten Political Philosophy that early either. I literally beelined straight to Mysticism to the get the +2GSP per turn thing as Greece. No way they have both Political Philosophy and Mysticism yet.
This is on standard speed as well.
But I'm noticing one AI getting 4.6GSP waaaaaay before Classical Republic.
You're very insistent that the AI cannot yet have a government, but have you considered the following, due to you playing on Emperor?
1. The AI starts with a second Settler, meaning they can have a second city up in potentially as little as five or six turns, which can start producing yields immediately after.
2. The AI starts with a free builder, allowing it to immediately improve it's lands and therefore the city. Due to tech unlocks, I assume this builder is most likely to build farms, which would let the AI grow more, and science and culture are earned from population.
3. The AI receives 3 free tech and civic boosts for every era. Note that I am not sure whether these are all applied at game start, or when the appropriate era is reached (and, if it's the latter, whether the AI or the game needs to reach that era).
4. The AI receives a 60% production and gold income bonus, allowing it to build and purchase quicker than a player can, which stacks with points 1 and 2.
5. The AI receives a 24% bonus to culture (and science and faith), allowing it to progress through the trees earlier.
If things line up like the following, you can quite possibly get those great scientist points:
AI starts with Early Empire, Political Philosophy and Writing boosted (alternatively, finds another civ early to boost Writing), finds a second continent, boosts Craftmanship with it's starting builder, and goes to get it's second city settled ASAP. Also, both cities have high food and production (perhaps they have several Spices, or just a number of 2-2 tiles). It rushes Monument in both cities. In the tech tree, it rushes Writing. After the monuments (and maybe some units), it rushes double Campus, gets Political Philosophy and Mysticism (which it could very well have boosted in the meantime, e.g. because it met religious city-states or found faith in a goody hut). It then puts in the Great Scientist card.
I think that's doable within 20-25 turns, and I haven't even considered any uniques yet. As pointed out, Jadwiga or Greece (would be Gorgo in this game, as you're Pericles) don't even need Political Philosophy to get a Wildcard slot, though that wouldn't explain the .6 very well.