The best theory about combat styles I read was about the shift from chariot mounted archers to massed infantry.<p>Prior to the collapse the regional powers in the Levant measured might by the length of their chariot lines.  The speculation was that skirmishers (possibly from the western Mediterranean basin) were employed to clean up after a volley-pass, and that these skirmishers realized that the horses would go down as easily as wild game, took that knowledge back to their homelands and returned en force.<p>Iron weapons aren&#x27;t quite as good as bronze (or so I am told), but can be produced more readily and cheaply and thus can equip a larger force.