Bret Devereaux

I’ll tag @Roelkonijn in on this, as he’s one of the foremost thinkers in the field. To my knowledge, we have very little source indications of how psiloi were organized. There’s some material and literary evidence that they sheltered behind hoplites in those periods 1/2

However, most analysis I’ve seen has them in a “open order,” a loose swarm that allows each fighter to function semi-independently. This is implied by the hit/run/hit tactics at Ithome, Sphacteria, Lecheum, and the Locrian attack on the Spartan rearguard. 2/2

That sounds right. The only indication of organisation is when Demosthenes divided them into groups of 200 on Sphakteria (Thuc. 4.32.3), but even for professional peltast mercenaries like those of Iphikrates we don't hear of anything similar.

We should probably assume that, like hoplites, mercenary peltasts and archers were informally grouped into the bands in which they were collectively hired. But unlike hoplite lochoi we don't see this reflected in combat. Their way of fighting required freedom from strict order.

When you fix light troops in place, bad stuff happens. We don't know what it looked like when Iphikrates' peltasts stood in the battle line at the Long Walls of Corinth but we do know that they were immediately routed.

Many thanks to both of you, this is very helpful! I assume, but certainly correct me if I'm wrong, that (at least from a Archaic/Classical Greek point of view) psiloi would largely be assumed to be less wealthy / of a lower social class than hoplites?

Yes, invariably. The form of one's military service was a prime conduit for conspicuous consumption: if you could afford it, you would be a horseman; if not, a hoplite (Lysias 14 and 16 offer the elaborately milked exceptions). Light troops were at the bottom.

If I may add, we ought to note that sometimes this was motivated by social competition, but it might also be encoded into law - especially viewed in the context of the broader system of liturgical service (rich required to provide public services like trierarchies).