The Makedonian phalanx -- why such depth?

[Giannis K. Hoplite]

Irrelevant to the phalanx depth,i just note that Diodorus' word for the skythed chariots is "tethrippon" which just means four horsed chariot.

Note also the consistent description of the phalangite shield as aspide. Clealry to Diodorus (and the others of our sources) a shield is an aspide is a shield.

Yes,it never meant something more than just shield. The word is unchanged till today. So we are lucky that they Greeks adopted a foreign name for the pelte because at different periods we know whate they are talking about(even if this word meant again just "shield" in the original language). We're not that lucky with hoplitical shield because there was no specific name about them,although some times they are called "Argolic".
Khairete
Giannis