With Killing off beasts the army loses some utility as well in the animus.
I am just looking into starting a Hordes force now and that is one of the big things I have noticed, how animus can stack with your warlock spells and other model abilities. That is another big difference between the two systems.
Scenery and modelling blog: http://shadowbadger.wordpress.com
I’m broniphobic just like I’m arachnophobic. I have nothing against bronies or spiders but I’d still scream if I found one in my bathtub !