Relative to the Brewers, the Cardinals are clearly a notch below us. Offensively, yes, they have some serious star power in Arenado and Goldschmidt (and even Edman has been at that level so far this year). However, their main problem is that they are getting virtually no production from the 6-9 spots in their order. O'Neill, expected to be their star left fielder and 3 hole hitter, has been so bad that he had to be moved to the bottom of the order and then benched for a few days, before going on the IL yesterday. Though, as you say, there is a distinct possibility that he turns it around and becomes the player he was last year, he is a guy that has always been hampered by huge swing and miss tendencies. The metrics are even down on his defense thus far, which is why he has been one of the worst position players in baseball by WAR. Meanwhile, Pujols, while not completely sucking with the bat, has been no more than average, and at his age, that is probably all you can expect going forward. He has also been getting more playing time than originally planned because Corey Dickerson, their other main offseason acquisition on offense, has been just as bad as O'Neill. In addition, Molina, the second 40 year old mainstay in their lineup, is increasingly looking like he's finished. Their shortstop production has been absolutely abysmal, which is why they're now moving Edman over and installing Gorman at 2B. That has the potential to backfire on them by taking one of their main producers off his best position. Another major disappointment for them has been Carlson, who also finds himself in the negative WAR territory. He remains very young and has shown better production, but the clock is also ticking on him becoming anything more than a decent player. Yepez and Donovan have been nice surprises, however, their prospect history indicates that they will probably not continue to produce at that level.
So, while the Cardinals may have us beat in sheer star power on offense with Arenado and Goldschmidt, it is highly questionable that they are better than the Brewers "top-to-bottom" offensively. They have multiple black holes in their lineup; we have just one in Cain. Whereas the bottom of our order has been holding their own for the most part, the Cardinals' has been continually eating away at the stellar production from the Edman/Goldschmidt/Arenado trio. And this doesn't even take into account the pitching side of things, where we have the Cardinals beat by a substantial degree....