In The Show, ERA (which is what you seem to basing your argument on) is not an attribute, but K/9, BB/9, H/9, and HR/9 are... Darvish has a much higher K rate, lower HR rate, and a comparable average against compared to Weaver and Cain. He has a much higher walk rate but that's offset by the huge difference in strikeouts. Darvish also has much better stuff, so him being rated higher makes sense to me...