High Imperial Roman army vs Late Roman army

[Frank]

That said, and while I am sure others will disagree, I still hold to the belief that the discipline in the army was not what it once was. Having troops billeted in cities, dependency on semi-independent "federates", the need to appease the troops to avoid being murdered, and frequent non-payment, must have resulted in SOME loss of unit cohesion/effectiveness. You don't see Stilicho or Aetius "decimating" their armies as punishment do you? Also, I believe it is significant that the army at Andrianople was baited into attack before the line was fully formed and the whole army was deployed properly.

I trend to agree about the discipline. There are just too many hints, how the emperors were enforced to pamper the soldiers in order to secure their reign and survive at all. However, late roman armies usually have been still pretty successful in the 4th century.

I would distinguish between the late roman army before the heavy losses at Adrianopel/Frigidus around 378/394 AD and afterwards. The heavy use of federates afterwards changed things significantly. In the West, the roman part of the army diminished even more, as more as the taxbase diminished (Britannia, Gallia, Hispania, Africa). The east-roman empire, managed the turnaround in the 5th century, also for the army. This long process was perhaps not finished until Anastasius' reign. So, if we criticse the late roman army, we should always mention, which part of the empire and which time we refer to.

After the reign of Herakleios and the loss of Syria, Egypt and Africa, I would even not call the East a Roman Empire anymore. Now after the reorganisation based on Themata things became even more different anyways. A fuly new era started. But thats just my personal view.