Old lags and young turks: A suggestion about the late Roman army

Fatally for the Roman Empire, the army's camouflage
department never internalised the fact that not being able
to see the enemy didn't necessarily mean that the enemy
couldn't see you.

While writing my chapter for the Cambridge History of War I delved briefly into the issue of the paired regiments of seniores and iuniores in the later Roman army.  As it turned out, the chapter turned out to be much too long and required much cutting.  Thus, as this was really something of an aside, this section ended up on the cutting-room floor.  I'm not sure there's an academic article in it so I thought I would try it out as a short note here instead.

I came to the problem in thinking about the nature of western European armies in the period immediately after the dissolution of the Western Empire - so, say, 475-600 - when there seems to have been an important age-based element in military service, with young warriors - pueri - serving in the households of the elite, especially those of the royal family and its officers.  Older warriors (variously titled) appear to have been a separate body, perhaps a cadre around which the pueri were organised.  In connection with comments about how the post-imperial western armies were the recognisable descendants of the very last, fifth-century, imperial Roman armies, I wondered whether this age-based organisation might not also have a Roman origin.

Many late Roman units attested in the western section of the Notitia Dignitatum are divided into iuniores and seniores.  Attempts to explain this division have generally failed to convince (the evidence being patchy and subject to decisive change with the discovery of a new tombstone, something which put paid to the theory that the division related to the division of the Empire, between older and younger brothers, in 364, for example) and it may be that a straightforward reading in terms of the relative age of the recruits has much to offer.  The iuniores would indeed be the younger, new recruits formed around a cadre of ‘NCOs’ and officers drawn from the older, more experienced seniores.  After successful service the soldier might be promoted to serve in the seniores, possibly eventually returning to the iuniores as an officer. 

A parallel with Napoleon’s Imperial Guard might be instructive.  Only about a fifth to a quarter of the definitely identifiable ‘brigades’ of iuniores and seniores recorded in the Notitia are found together in the same army (though most are at least in the same half of the Empire), but equally, for example, the ‘Voltigeur Grenadiers’ of Napoleon’s Jeune Garde were often serving far from their elder brothers in the Moyenne Garde’s ‘Fusilier Grenadiers’ and the Grenadiers of the Vieille Garde (the corps’ ‘parent regiments’). 

Someone is sure to have proposed this before.  Does anyone have any thoughts?