Inasmuch as it has been determined the bones were reburied 300-600 years after their bog interregnum, seems to me pretty obvious that in that long meantime of those 3-6 centuries the bones were jumbled together. Once people found them and decided they had to be buried to save their souls or something they believed in, they tried to reassemble them the best they could, not thinking they had to get everything right but just to give them a form, and that's what's been found. It's not that "the head fell off so they put another on", the bones were probably in a collection that, as the article states, was added to centuries apart. The reassemblers who buried the bones did a pretty good job of it.
The idea the reassembling was deliberately jumbled is far-fetched. Ancient peoples were not so much interested in the symbolic images of their religious purposes---that lazy behavior is of a much more recent origin, when the somewhat-religious started going thru the motions and didn't really believe what they were doing, except symbolically. These people were not attempting to represent an idea but the literal body, for if they didn't get it right as well as they could they would fear a bad reaction from the deities they were trying to serve by reburying them. We don't believe in such gods, the evolution of religion having in the meantime absorbed awareness that we are One so what difference would it make today, or as far back as medieval days, to put the bodies correctly together? The Chilean undertakers that used sea lion skin and whatnot to patch up their mummies did so because pieces were missing, the idea being to make the body as whole as possible without the Western fixation that everything is separate so skin from another mammal wouldn't work; the Chileans had a much more sophisticated view of the world, which was interrconnected and indisoluble from everything else, which we are slowly returning to after 2,000 years+ of strict and false differentiation between creatures.
These rituals were not more "bizarre" as the 21st century Brown insultingly and ignorantly concludes in his infinite wisdom, they make perfect sense when you stop imposing modern fast-food-type religion atop deep, ancient spirituality.