The Slytherins' protectiveness of Harry in the fanfiction could be a result of a deeper understanding of Harry's situation. In the world of Hogwarts, there are many complex relationships. Slytherins, who are often thought of as only interested in power, might in this fanfiction realize that Harry is a key figure in a much larger struggle. Their protectiveness could be an attempt to safeguard the future of the wizarding world. It's a very interesting take on their characters and shows that they are more multi - faceted than the original stereotype would suggest.
Well, it completely flips the stereotype. Usually, Slytherins are seen as sly and self - centered. But in this fanfiction, being protective of Harry shows that they have a sense of loyalty and care that goes against the common perception.