All throughout its many seasons, Sam and Dean battled a number of different monsters. Even when the odds are stacked against them, the brothers get ahead. Now, in Season 15, they fight Chuck/God, once an ally, now turned a villain. We're not sure if they will win, but the brothers will die trying if that is what it takes.
It would seem that taking on the villains in Teen Wolf would be easy for the hunter brothers. However, there are some villains that they could easily beat, and others that it's unlikely that they would defeat.
Could Beat: Jackson
Jackson was presented as a villain in the first two seasons of Teen Wolf. First he was just a bully, and then a kanima. Jackson is initially unaware that he is a kanima. He turned into this because of his emotional issues when Derek tried to turn him into a werewolf. In a sense, a kanima wants a friend or to be ordered, controlled by someone else.
Sam and Dean would be able to beat Jackson sooner than McCall gang did because they would see what's going on sooner. Additionally, while Sam and Dean have little tolerance for bullies, they do understand what it feels like to be abandoned and alone. Based on their sympathy, they could get to Jackson faster.
Could Not Beat: Kate Argent
Kate reminds us of Bela, just a little, in that she's devious and always has an ulterior motive. In addition, she's a survivor and uses her sexuality as a weapon. However, that is where the comparisons stop. While Bela was often motivated by money, she actually had more compassion than Kate. When Kate was a human, she killed innocent people--humans and werewolves--with little remorse. When she became a werejaguar, she was nearly unstoppable, creating beasts out of humans with little regard for their lives.
Since Kate is somewhat like Bela and Bela always outsmarted the brothers, Kate would, too. We could see Dean attracted to Kate, and we could see Sam think that he can save her. In the end, she'd be the villain they'd struggle to try to beat for a full season.
Could Beat: Theo
Theo, the first chimera created by the dread doctors, changes throughout the seasons in Teen Wolf. First, he is a villain, manipulating Scott's pack against him. He wanted power and his own pack. The dread doctors helped grant him his own pack of chimeras, and when he realized that killing one of his pack members would give him a charge of power, he did it. Then he was a useful source of information, but still someone Scott's pack didn't trust. Finally, he redeemed himself by saving others.
Theo displays little fear of Scott's pack and no fear of the consequences of his actions. Dean could change that. Dean has little patience for this behavior, and he could scare Theo into being a better person quickly. Additionally, while Theo is smart, both the Winchester brothers are smarter. After all, they worked with Crowley and made even the King of Hell into an ally.
Could Not Beat: The Dread Doctors
The Dread Doctors are scary immortal scientists who seem to have unstoppable power. They work to bring back La Bete (Sebastien Valet). They take people and experiment upon them, making them chimeras. If the chimeras are a failed experiment, the dread doctors kill them. Even Malia, a werecoyote, can't fight them.
Although both brothers are smart in their own ways these villains would be hard to beat. More so, we could see the dread doctors experimenting on one or both brothers. If Sam and Dean are strong enough to be vessels for Lucifer and Michael, they would be strong enough to become chimeras and survive.
Could Beat: La Bete
La Bete is Sebastien Valet. The dread doctors have been trying to resurrect him, and unfortunately, they find the perfect host in Mason. When he's transformed into La Bete, Mason has no idea what's going on or memory of what happened. Little by little, Mason (a good person), will be replaced by Sebastien, until in the end, Mason won't exist anymore. The McCall pack saves Mason, but it takes time for them to realize that Mason is La Bete.
While the Winchester brothers would have a hard time in beating the Dread Doctors, they could beat La Bete. Both brothers would be able to destroy La Bete by getting through to Mason earlier. Also, Dean would have used Sebastien's arrogance against Sebastien.
Could Not Beat: Tracy Stewart
While most of the chimeras held onto their personalities and values despite their transformation, Tracy became a totally different person. She even killed her father, the man who loved her and tried to help human-Tracy through her night terrors. Had Theo not killed her, it's unlikely that the McCall pack would have been able to beat her.
Sam would believe that he could save her. Since his own past made him one of the special children, fed demon blood when they were infants, he would understand having a transformation forced upon you. Additionally, both brothers would have a hard time killing a teenager. Sam would try to reach out to her, but unlike with Jackson, he would fail with Tracy.
Could Beat: Berserkers
Berserkers wear the pelts and bones of animals, eventually losing their human side. They become like animals but without consciousness or individuality. Kate Argent has berserkers with her, and she can create more. She tries to make Scott into one, but luckily Scott still hung on to his humanity, just enough, for his friends to rescue him.
While Kate is a foe that the brothers couldn't beat, Sam and Dean could easily defeat the Berserkers. This would be an easy day of hunting for the brothers, something that they could have done in Season 1 or 2.
Could Not Beat: Desert Wolf
The Desert Wolf is not a main villain on Teen Wolf, but she's in the background. She is Malia's mom, and she has no warm and fuzzy feelings for her daughter. The Desert Wolf wishes that she didn't have Malia since part of her power went to Malia when she gave birth. No doubt, the Desert Wolf makes Peter Hale look like a good guy, like the better parent, which shows how bad she is.
Both Sam and Dean would have difficulty fighting The Desert Wolf. She's smart and coy, and she could easily deceive them. Sam would be convinced that they could save her. Dean has a soft spot for mothers. But in the end, she could use their compassion against them because she thinks pragmatically, out-witting even the hardest opponents.
Could Beat: Nogitsune
The Nogitsune is a dark trickster spirit. It likes games, and it likes control. It likes chaos and destruction. In Teen Wolf, it possessed Stiles, and luckily Scott figured out how to win and save his friend. It was a challenge though.
This would be a harder villain for the boys to beat, but they could. Most likely, they'd have more lore available to them from Bobby's intensive research or from the bunker. Also, both Sam and Dean are faster at figuring things out than Scott is, and they would have realized how to save Stiles earlier.
Could Not Beat: The Ghost Riders
The Ghost Riders come and take people away into another world. Not only are these people "vanished," but their friends and family don't remember them. The vanished people gather in a train station and most seem to have little memory of their lives. Later, their towns disappear.
The McCall pack can't even beat the Ghost Riders; they redirect them. Sam and Dean would have little luck either. While they would have problems just redirecting the ghost riders to take another town, they wouldn't know what else to do. Sure, they would try, but as Death once told Dean, there is an order to the universe, so some people must die, and some towns must vanish.