So I was flipping through the Brawl forums and came across this message thread:
http://www.westgamer.com/phpBB2/viewtopic.php?t=7181
It's basically a discussion on whether or not you can use Mighty Blow with Claw.. and before Stash has a brain hemmorage, the consensus is still yes. What I found interesting was the discussion on when you use Mighty Blow. If you go through the thread discussion, they post a few links to the rule book that indicates that you don't have to declare when you use Mighty Blow as in previous editions. Now, you roll your armor penetration and if you need it, you can decide to use it after you roll. If you make your armor penetration roll though, you can save your mighty blow for the injury roll.
Anyway, thought it was important to note and discuss. Probably no point changing it now with one game left, but miught be good to note for next league. I couldn't understand why Mighty Blow was such a talked about skill through the Brawl league, but when it using it this way it becomes very, very scary!