Thanks for helping there Drew. The race grading can be a real pain to work out, as the race organisers pick the grading for their events. As is clear in this case, they often over (or sometimes under) grade the race.
We recently redone our grading guidelines, which will be shared with the organisers. Info on the update can be found here: http://www.runultra.co.uk/Forums?forumid=2&threadid=242
We also changed the hardest grade from Ultra to Brutal. As that prior title was clearly confusing.
Good luck if you end up racing it Rusty!