How can the meaning of the verse: "And We have not appointed guardians of the Fire except angels" be reconciled with the meaning of the verse: "Not equal are the companions of the Fire and the companions of Paradise. The companions of Paradise – they are the achievers of success"?

In the first verse, "the companions of the Fire" refers to the angels entrusted with Hellfire, and they are associated with it because of their work within it by Allah's command. As for the second verse, the intended meaning is the disbelievers who deserve punishment and reside therein. There is no ambiguity or problem in this understanding.