Pausanias on Achaean armament, ca. 200 BCE

[Komanos]

Another interesting way of looking at this: Sellasia. We know that Antigonus came with a contingent of peltastai (3,000) and the phalanx (10,000). Now, in the battle we hear from Polybius that the "chalkaspides," in mixed lines with the Illyrians, launch an assault on Eucleidas' position. Meanwhile, the rest of the Macedonians, he tells us, attacked Cleomenes in the pike phalanx.

So, either the chalkaspides = peltastai in the reign of Doson, or the peltastai were part of the contingent in the assault on Cleomenes. I lean toward the former, with the chalkaspides becoming the main phalanx contingent in the time of Philip, since the attack on the Euas hill seems more like the sort of action we'd expect from peltastai rather than pure phalangites.

And Inaki, I agree that the pure understanding of the peltastai should be as an elite light-medium troop. I think most of the disagreement has been reconciled, having recognized that they could at times form the phalanx.

And as for the inscriptions you'd asked about, they can be found in the Appendice Epigraphique to Melethmata 30, Hatzopoulos, L'Organization de l'armee macedonienne sous les antigonides. You can also bring them up, without notes and discussion, on the Packhum database. For what its worth, the main part worth mentioning is that the peltastai were never older than 35, and part of the larger agema of elite Macedonians, which also included the hypaspistai and the agema.