Complete shack on divert options (overall). BUFF options are relatively small since they have a 140+ ft taxiway requirement thanks to the tip gear. However, there are some places in Europe that can do the trick as well as Lajes.
Well, that depends... [/WIC mantra]
If volume was an issue, MORE B-52s might have been preferable as they could be split up to take out more DPIs over a wider area. With 4 BUFFs, you could cover more locations, but with fewer bombs. I'm just saying that there are other ways to look at it. This problem would have been solved with internal weapons carriage upgrades the BUFF has been complaining about for 20+ years.
As for the 4-ship comment, BUFFs do train for 4-ship formations. I've personally been involved in a 4 bomber on 3 tanker mission
Pretty sure AFRICOM/EUCOM made that call with some ACC lobbying. I don't think AFGSC said "Don't use our bombers! Take the ones that ACC has!" (though I've been proven wrong in the past...)