What happens in Manhattan, stays in Manhattan. It's just unfortunate that what seems to happen in Manhattan is a lot of Doctor Who plots where the writers have been higher than the Mighty Jagrafess of the Holy Hadrojassic Maxarodenfoe (a name that was definitely conceived while taking wacky baccy). In this instance of "America is another country so let's just go with it", the writers gave the Daleks some porcine sidekicks who prove absolutely useless in every possible way. Much like Bad Wolf, the writers clearly love giving the Daleks poorly written workers when it's clear that, for enough money, humans would happily do the work for them - that's how they staged Mr Diagoras and Dalek Sec making beautiful music together in the first place. Or the workers on the top of the Empire State building applying it with Dalekanium. The pig slaves are some poor writer's idea of a bad joke that got lumped into the episode as a B-story because the writers did not want to reveal the Daleks straight off the bat. That said, perhaps one of them just wanted a bacon sandwich while high, and jotted it down while no-one was paying attention.
