Quality of Late Roman Legions

[Aryaman2]

I think there is some true in the Barbarisation of the Roman Army, but already in the V century, not in the IV, despite a number of High Officers of Barbarian origen. For instance, when Stilicho was murdered his army practically dissolved because it was largely a private army with many Barbarians in it. Remember also the large number of Goths in the Army of Theodosius at the battle of Frigidus.
As for the impact of Barbarians in the Late army, it has been pointed out that Barbarians were in Roman armies in other periods, the difference could be in the proportion, but also in that they were regarded at least as worthy if not more than Roman infantry to the extent that Romans changed to copy Barbarian ways.
An example, earlier Numidians or Germans could be essential for some Roman victories, but Roman infantry was still held the higher estime by his generals, but in the Late Empire we see generals with a barbarian body guard, and we are told that they had preference for such or such Barbarian nation. All that would be very detrimental for the morale of Roman soldiers, and the decline of infantry in the V century is very clear, and later the army of Belisarius is basically a cavalry army whose elite units are Barbarians. That is basically what Ather Ferrill says, and I think in general he has a point.