Harry/Draco, as an “enemyslash” pairing, must negotiate a somewhat different “semiotics of masculinity” than Harry/Ron, and Harry/Snape, as both “enemyslash” and “powerslash,” is a different beast altogether.
The second most popular Potter slash pairing is Harry/Snape, which belongs to the powerslash category, and again defies findings of early fan fiction studies focusing on buddyslash.
2011, Catherine Tosenberger, "Homosexuality at the Online Hogwarts: Harry Potter Slash Fanfiction", in Over the Rainbow: Queer Children's and Young Adult Literature (eds. Michelle Ann Abate & Kenneth B. Kidd), →ISBN, page 343:
Order of the Phoenix featured Harry and Snape (a powerslash pairing par excellence) forced to become uncomfortably intimate with each other: Snape is teaching Harry how to prevent Voldemort from reading his thoughts by...reading Harry's thoughts; […]
Although the second most popular pairing in Potter slash fandom, Snape/Harry (or Snarry), could be categorized as enemyslash, it is also a prime example of powerslash.