Weapons for elevated overseers

What weapons do you all use to deal with these guys? The only thing I've found so far that deals with them quickly is the heavy machine gun and HMG. Even then though it's insane because they can tank more rounds than a hulk even though they have a smaller hotbox AND move quicker.

As far as primary weapons go though I haven't really found anything that deals with them very efficiently. Can anyone suggest anything for these guys? They tank so much damage for their size it honestly feels like someone added an extra digit on accident when coding their hit points.