Acceptance of Plato's testimony in the Parmenides raises more problems than has commonly been realized. Plato's divinatio may have hit the truth, but to have this confidence involves an act of faith. If anyone wonders what other theory we may put forward regarding Zeno's treatise, he may take notice of the fact that in the Phaedrus Plato mentions Zeno in the company of rhetoricians like Thrasymachus, Theodorus, and Gorgias. In the devising of new methods and argumentative techniques he remains a pioneer.
Solmsen, Friedrich, "The Tradition about Zeno of Elea Re-Examined" (1969). The Society for Ancient Greek Philosophy Newsletter. 88.