I find the Crawlers pretty easy to headshot, and [the Knights](https://gaming.stackexchange.com/questions/92447/tactics-for-taking-on-knights) seem to at least take a lot of damage if not one hit when their shields are down, if aiming at the head. The Watchers don't exactly seem to have a head, and focusing on the center "head thing" doesn't seem to improve the take down time. I'm finding them super hard to eliminate, and they often overwhelm me. Do they have a weak spot like other enemies?