Actually, I don't think Meditation needs a tweak. I saw the same civilization with Judaism and Buddhism only 5 times in 20 autoplays. I think with Monotheism moved backwards, it's easier for an AI to go off track just to grab Monotheism, found Judaism, and then return to other research. The most common pairing I saw was Christianity-Islam (10 times, 1 by conquest). This usually happens to the #1 civ on the scoreboard. The second-most common pairings, at 9 times each, were Buddhism-Taoism and Taoism-Islam. I think the Islam pairings are simply because whichever civilization is out front by the late Classical (pick up Taoism) or early Medieval (Christianity) stays in the lead long enough to get Islam. I would like to do something to Philosophy, but the problem is that Philosophy is Meditation's only exit point, and I can't see a way of either breaking that link or making Philosophy harder to reach.