Just a thought. While I agree that CTA and Beast will increase your life and damage, you need to way the hassle of switching from Leoric, to CTA, to Beast. I just use Leoric and I have no trouble killing anything in the game quickly. For ease, you may want to look at just using Beast on switch. You really can't go wrong with either setup.
BTW, I'm starting to believe that the necro summoner may be the most powerful build in the game. He doesn't do the most damage or killing speed, however there's nothing in the game he can't kill efficiently. I can go games without ever being touched. Anyway, have fun!!!