As weird as the title, but that's true, in M2TW kingdoms, certain skirmisher units get cannot_skirmish ability in the EDU (such as Deisi Javelinmen, Welsh Skirmishers, and Kurdish Javelinmen). I wonder if this ability could be used to represent heavy skirmisher class such as Peltastai or Archer Spearmen, who also expected to stand and fight. In this situation, the AI will treat them still as missile units, and use their missiles effectively, but they won't run easily when some enemies goes near them. This was doubly true for Archer-Spearmen, since IF they run, they didn't get their expected role to withstand (light) cavalry charges. And peltastai with skirmish mode on (as the AI often does in sieges, and even some field battles), actually messed up their staying powers.