Fear The Walking Dead just proved the Stalkers are not the main villains of season 7. Introduced in the season 7 premiere, it seemed the Stalkers would be the new antagonistic group Morgan and the others would face. Season 7, episode 4, "Breathe With Me," however, has substantially diminished their threat level. If the Stalkers are set to be the main villains of Fear the Walking Dead, they have made a pretty poor first impression.
The Stalkers have so far made three appearances in season 7. In the Fear the Walking Dead season 7 premiere, "The Beacon," they are shown ambushing Strand and Will as they lead an expedition to find Alicia. Their attack leads to Strand's men being killed by zombies. They are next introduced in "Cindy Hawkins," where they attack June and John Dorie Sr. as they reside in Teddy's bunker. A particular trait that makes the group stand out amongst other groups is that the Stalkers take the clothes of zombies. They are seen doing this in the cold open of "The Beacon," and it sets them up to be an incredibly creepy villainous group.
Despite their antagonistic nature, however, the Stalkers are not a major threat, or at least not major enough to be the new main villains of Fear the Walking Dead. "Breathe With Me" proves this by showing Josiah completely embarrass one of them while helping Sarah search for Wendell. Even beyond that, their previous attacks have been largely unsuccessful; in the "Cindy Hawkins" episode, for example, all three Stalkers who attack Teddy's bunker die. Similarly, while their ambush against Strand and Will leads to the former's men being killed, it's more because they were attacked by zombies in the area as opposed to any direct action from the Stalkers. The Fear the Walking Dead episode found Strand and Will also managing to escape the Stalkers. Since the Stalkers' main goal was likely to obtain any clothes and equipment Strand and Will's group may have had, the ambush is largely a failure.
After the previous failed attacks began diminishing the Stalkers' threat level, Fear the Walking Dead season 7's "Breathe With Me" seals the deal when Josiah, Sarah, and Rufus come across one while searching for Wendell. The Stalker is introduced trying to shoo Rufus away when the dog begins barking at him. Josiah demands the Stalker strip when Rufus catches Wendell's scent on his clothes. Instead of putting up a fight, the Stalker immediately complies. Furthermore, when Sarah tries to attack him in the barn, the Stalker opens a pen full of zombies to distract her and Josiah while he makes a quick run for it. This proves that the Stalkers are not a force to be reckoned with and their survival has largely been reliant on the zombies they have at their disposal rather than their combat proficiency.
Ultimately, it's been proven that the Stalkers are (at least initially) not the main villains in Fear The Walking Dead season 7. It's more likely that they are just another group trying to survive the nuclear apocalypse that just happens to be coming into conflict with the other survivors. That being said, they have just acquired the warhead that did not explode when Teddy launched the nuclear missile. If the showrunners intend for the Stalkers to be the main villains of Fear the Walking Dead, what they plan to do with it could be what catalyzes their turn into true villains.