How would you characterize the difference between what Socrates wants from and wants for Cleinias, and what Euthydemus and Dionysidorus want from and for him?
Socrates wants Cleinias to love wisdom and desire to be virtuous. Socrates believes that the love and desire can be awakened in Cleinias, and awakened in conversation (elenchus); he demonstrates how that is to be done (278e-283a). Socrates is doing what he asked Euthydemus and Dionysidorus to do earlier (at 275a).
What are Euthydemus and Dionysidorus doing by contrast? At 275c, Euthydemus reveals that he and his brother have no stake in Cleinias' moral improvement (as Socrates does). All they care about is Cleinias' willingness to answer their questions. So how is their conversation (eristic) different from Socrates'? What are they trying to teach Cleinias? Anything? What?
Ponder these questions. Also, think carefully about the brothers' eristic: how does it work? Try to develop a formula or recipe that guides what they do.