Why are they good bed-fellows, other than the fact that they're both huge? Well, ABI has a big lead in the US, and has blocked SABMiller out of the second largest profit pool (Brazil) and the third (Mexico), so they can combine to create a behemoth without fear of antitrust concerns, says Carlos Laboy and fellow analysts of Credit Suisse. Also, ABI has control of their brands in China, while SABMiller does not control its China which "could become a problem over the long-term when China moves the earnings needle."