My main tank/mage champion who serves at my lord's meat-shield is often sent into battle to sweep.
I noticed however that when I added a Warg to her, the game hung about 30 seconds after each sweep. Currently, I always Beserk her and send her in. She is also using the Druss Blade, which like a 1920g Red sword which ignores 66% of victim's defense. Can we say instan-kill? We sure can.
Still, the game hangs oddly after each Sweep, check it out.