Six Numeri for Honorius

[Nathan Ross]

The eastern Notitia was of indeed out of date by 410

Personally, I suspect the entire Notitia was out of date by 410, and probably had been since before the Frigidus... but the less said about that the better, perhaps!

the Epistula Honorii.

Yes, I came across that one just a couple of days ago - very interesting. Seniores, Iuniores, 'Speculatores' and 'Britannici' - they certainly sound like genuine units, and if the letter itself is genuine and the presumed date accurate then we have perhaps the last evidence for regular Roman military units in the west...

the sending of those 4000 men as part of a post-Stilicho treaty

Surely Zosimus is implying that the 'alliance' dated to before Stilicho's death, since the troops had been expected 'since his time'? But it's a very vague and hazy reference...