Slitherine

One thing that I don't understand in the Principiate Roman (and to some extent in the Later Republican Roman) list is why it does not allow cohors equitata to be mixed BG of Cavalry (Armoured, Average, Drilled, Lt Speasr, Swordsmen) combined with Javelinmen (LG, Unprot, Ave, Undrilled, Jav, Lt Spear - or just Lt Spear). As an aside, I never understood why this was not allowed in DBM but I started playing that too late to influence the 2nd edition army lists. I know that the foot in the cohors equitata were deployed seperately most of the time but they did deploy combined sometimes.

The evidence for the introduction in Late Republican Roman armies is in Caesar's de Bella Gallico (and possibly de Bello Civili). Its use in the Principiate is described in the parts of Frontinus that Vegetius relates. These are referred to by Prof Eric Birley (from memory, so can't remember where) and on P222 of the 1979 edition of Graham Webster's The Roman Imperial Army. I am not sure if the idea has been discredited by later authors, especially Goldsworthy.

Can I ask the rules authors and list compliers why this is not allowed in FoG?

The Cohors Equitata was a strategic way to provide some combined arms locally around the Cohort's base fort. It is most unlikely that the horse and foot fought together as a battle group in open field battles. Moreover the infantry element were normal auxiliaries.

Legions also included cavalry at various times, and did not fight in mixed bodies.

Richard, that makes some sense. Are the cases where the cavalry are 'stiffened with lightly armed foot soldiers' considered to be too exceptional and/or theoretical to not justify being included i Fog? The quote is from a translation of Vegetius. At Pharsalus Caesar used mixed units of light foot and cavalry 'Caesar ordered the footmen to thrust their javelins upwards into the faces of the horsemen ... Subsequently the cohors equitata became a regular unit of the auxilia. This is a quote from Webster. Is he misreading events from one battle, not understanding that your explaination above means that they really were different things though superficially the same?