I messed up and put in "Enforcers" where I should've put in "Overseers". Oops. Edited that.
While they have that slight resistance, the Overseer's 100 strength Block is still going to add a lot to Thunder attacks, so maybe that'll help bust through them. They also can get hard-walled by a strong enough shield despite having a DEF drop on hand, so if they don't have any backup, they're toast. Having a big hit ready to take an enemy from >25% to 0 also shouldn't be too tough to pull off at this point.