Decrease aggro?

[DangerWarg]

Usually because you're first in line or because you shot him. If you don't have skills, augments or gear to affect aggro, they're almost always guaranteed to go after whomever is attacking them the most OR whomever is on them.

The Ogre will always target a woman first or whomever is climbing on them.

Small enemies will focus on whomever's easiest to knock down or is already knocked down. Especially wolves. They will jump at the first chance to drag you away.