Hippeis, not Hippies

[Paralus]

As I have said many times, I think the 300 were 100 x 3. The tripartite nature of Spartan numerology cannot be underestimated. The Gerousia had 30 permanent sitting members and I suspect these senators were drawn 10 from each Dorian sub-tribe. That would be 10 from the Dymanes - 10 from the Pamphyloi - and 8 plus the 2 kings from the Hylleis.

Quite. Xenophon, Hellenica 3.4.2:

Now while the Lacedaemonians were in a state of great excitement, and were gathering together their allies and taking counsel as to what they should do, Lysander, thinking that the Greeks would be far superior on the sea, and reflecting that the land force which went up country with Cyrus had returned safely, persuaded Agesilaus to promise, in case the Lacedaemonians would give him thirty Spartiatae, two thousand emancipated Helots, and a contingent of six thousand of the allies, to make an expedition to Asia.

Now, aside form the Lacedaemonians running about in a state excitement (for which read near panic) about an expedition almost certainly aimed at Egypt, the number is interesting: thirty rather than twenty or fifty.