I disagree. I had originally aligned "weekly mass" with "sweat the details", but "Sunday morning crowd" is defined by the article as the true Catholic swing vote. Let's look at the top three conservative-voting Catholic groups again:
55% McCain, 43% Obama - Weekly mass-attending Catholics
52% McCain, 47% Obama - White "regular-mass-attending" Catholics
51% McCain, 49% Obama - White Catholics
In each of the last three Presidential elections, the Catholic vote was consistently split about 55/45 between the main candidates. And all of the above groups demonstrate a "swing vote" kind of split. I don't define a 55/45 split as an overwhelming vote for one candidate, and that's why I don't associate "weekly Mass attending" (nor does the article) with "sweat the details", but instead why I chose to leave that last section blank. The article says the "sweat the details" group (and I quote) almost always backs the Vatican on doctrinal matters. I don't equate 55/45 with "almost always".
FWIW, I am likely to concede that there's a conservative Catholic demographic - possibly the "sweat the details" Catholic - who voted overwhelmingly for McCain, but as you rightly point out, there are simply no polling numbers that capture it. As this article states (and I'm forced to agree), it must be a "small slice of the American Catholic pie."
That means that the Sunday morning only folks are somewhat more pro-Obama than your 55-45 McCain split, but only slightly, since the sweat the details people are a much smaller faction. If you assume that the weekly mass attendees are 90% sunday morning only and 10% sweat the details, and the StD people went 90% for McCain, that means that the sunday-morning only people went 51% for McCain.