Hi, I just posted under the Storm of Magic thread, but I noticed the discussion here. Basically it is about adding the Monstrous Arcanum units - the rules are now available FREE on the forgeworld site:
http://www.forgeworld.co.uk/fwDownloads
The other comment was that I noticed in the official Warhammer World event they said these can be included as Special choices. And finally, a nice concept is to take a look at the monster table in the above link, and allow a way to let monsters with "Kinship" appear as Special choices.
I haven't used the utilities in Army Builder, but I am a programmer, and would be happy to get the data added if you are interested in adding the Monstrous Arcanum units.