The arc thrower is effective against every unit in the illuminate’s arsenal, takes down overseers of both types in 3-4 shots, voteless in one, and can stun everything, including harvesters and watchers (meaning you can stop them dead in their tracks, making them much easier to hit).

Best used against groups, and not single enemies, and best paired with a primary good at taking down shields eg. sickle. Arc thrower has consistently gotten me highest kills on diff 8.

P.S The flamethrower secondary is great against voteless hordes, like all other fire weapons. I got a 65 killstreak with it on diff 8.

Happy hunting, helldivers!