Just a warning to all testers. Apparently, testing using the Sparring Targets in your lairs would mess up results of various tests. Not sure how this works (as I am incredibly unlucky with my Test Server Boxes and never got a Sparring Target even once) but someone PM'd me and said it was due to it having less HP than the Watchtower/HoD versions and causes the remaining damage dealt to it not to register. This has been confirmed by AIpha too.