That really depends upon what standards, or from whose point of view, you define "equality".
Zaroff would be able to argue that they are equal. Zaroff and Rainsford are both human and have courage, cunning, and ability to reason, the three things f says make humans the best to hunt. They both have immense experience as hunters, as well.
On the other hand, there are several factors that show them unequal. Zaroff has dogs and weapons to hunt with, Rainsford only a knife. Zaroff has his servant Ivan to help in the hunt, Rainsford has only his cunning, experience, and intellect. Zaroff has intimate knowledge of the island and its many hiding places, Rainsford does not. Zaroff has the advantage of a comfortable bed, good food, and a good night's sleep; Rainsford obviously does not.