That explains why I keep getting more policies before rationalism than I expect. I noticed that not everything is properly scaled by 2/3. For example, you get 66 gold per city from the religious belief instead of 100. Which is correct. But then universities cost 480 instead of 440. (660*2/3)
Similarly, one faith CS buys you a pantheon. Lots of little bugs like that. But I don't know for sure that 3/turn is broken, because every 2 turns on quick equates to 3 turns on standard. So 6 culture every 2 turns is actually like 6 every 3 turns. But they also round the policy cost to the nearest 5, sort of.
So, the first policy is 15, instead of 16.3333. The second policy is should be 26.6666., etc.
So you're probably getting some bonus points in there... ?
One thing that is definitely different (IMHO) is that you need more scouts to find everyone by the equivalent standard time. Any delays are much more significant. It makes sense though that with movement rates the same, but 50% more time passing while you move, that you'd need 50% more scouts, so 3 instead of 2. But that hoses the early build queue... But that extra scout... Well that certainly favors liberty. But only if you get a culture ruin. Waiting 15 turns for your first policy is horrible. And you absolutely can't go monument first on quick because you need to scout ASAP. Sucky dilemma.