How does the allusion in this passage connect to the central idea of the passage?  The allusion emphasizes the need for compromise between human beings, just as the gods are forgiving of human faults.  The allusion introduces the idea that, although the two men are very powerful and command armies, they are not gods but human beings.  The allusion emphasizes the size of the faults that Brutus sees in Cassius, which will lead to an honest discussion of the roots of the friends’ conflict.   The allusion to the gods introduces the notion of fate, suggesting that the relationship between Cassius and Brutus can be repaired only if it is fated to be.