Dracovish can be checked by Pokemon that are immune to Water such as Seismitoad, Gastrodon, and Mantine; it's quite weak when it's not using Fishious Rend. You can also offensively check it with Dragapult and some other Choice Scarf users like Hydreigon.
Dragapult's rather susceptible to specially defensive Fairy-types such as Clefable and Sylveon. It also struggles with Mandibuzz and Gastrodon. It can be checked offensively by Aegislash, Choice Scarf Hydreigon, and Bisharp to name a few examples.
Similarly to Dragapult, Hydreigon's also susceptible to the aforementioned specially defensive Fairy-types. However, it doesn't really struggle with any of the other Pokemon mentioned. It can however be checked by Conkeldurr and some other Pokemon like Dragapult and Choice Scarf Hydreigon offensively. Hydreigon tends to struggle to set up as well, so not giving it any setup opportunities can oftentimes be sufficient in dealing with it as well.