I've just finished reading Michael Kulikowski's "Imperial Tragedy". It's not only given me some fascinating new insights into the final century of the Western Roman Empire, but suggested some changes to Late Roman and African Vandal lists for next time someone is inspired to update the lists.
Patrician Roman (Western): The steady disintegration of the Western Empire suggests that by around the middle of the 5th century (say, after the death of Aetius) that Western Patrician Roman armies should have a limit placed on the number of regular elements, perhaps no more than 20 regular elements. That way the player is forced to use either a lot of foederate foot or allies. The problem at the moment is that, even though the list notes talk about the need for Patricians to use allies, even an army of Odoacer can be fielded at 400AP with an entirely regular army of three generals, Kn, Cv, LH, Bd, Ax, Art and Ps.
African Vandal: Kulikowski points out that after the death of Gaiseric the Vandals suffered a series of defeats at the hands of both Goths and Moors, which suggests that from about 480AD all Vandal Kn (F) should be downgraded to Irr Kn (I). Frankly that's still fairly formidable, and will give Cv opponents plenty to sweat about, but they'll also be considerably more fragile. It would also make Gelimer's Inertness all the more of a problem, as he's going to have to pay PIPs to move those great lumps of Kn anywhere.