I'm pretty sure this is a glitch as its the only archer type that one shots. As of this post I've been cheated out of clearing Thorne Liro's first arena mission because they magically smash over 4k health do to shield bypass on a person running a rebel. This doesn't just happen to this shield type but all shield types since shields add hp which is apparently being counted as the shields too and wiping people out by hitting straight to the base health. I'm assuming base health doesn't increase, thus the one hit kill.