Ten great generals

[Kai]

Stilicho's policies were very detrimental to the empire though, while Aetius' benefited the Empire more than they hurt it. Furthermore

You know, this could be seen in a totally different light. Not saying this is the absolute truth, but different perspectives are always helpful; and I am going to present a radically different one:

Aetius had established a military dictatorship in which he pulled the strings of the marionette Valentinian III. Outmatched and powerless, the civil elites tried to gain support, but Aetius had cut down all opposition - literary so. Therefore they turned to a more powerful ally, offering him the hand of Valentinian’s sister Honoria: Attila the Hun. The fight between Aetius and Attila was not that of a barbarian vs a Roman, one trying to destroy the Empire, the other trying to save it. It was a struggle for the domination of the western Court. Aetius simply knew Attila had a military force to match his, and an heir to Honoria would produce a candidate to the throne being the puppet of Attila, not his.

When the fight for the western Imperial Court ended with Attila’s death, Aetius was the undisputed master of the west, and married his son to the Emperor’s daughter. I may quote H. Börm now:

It is somewhat surprising how brightly the so-called “Last Roman” Aetius is portrayed in ancient sources and sometimes even in modern literature. Basically however he differed from power hungry military commanders like Genseric merely by placing his headquarters at the Imperial Court of Ravenna, therefore dominating the central administration and the emperor. It is probably for this reason people tend to confuse his interests with that of the Western Roman Empire, but those coincided only partially.
Valentinian III, meanwhile about 35 years old, certainly had a more realistic judgement about what his supreme commander was doing, knowing that he was just exploited being a figurehead for Aetius, lending the appeal of legitimacy to this regime. After all, he had watched Aetius at work all the years. (Westrom von Honorius bis Justinian, 2013, p.90; my rough translation)

Valentinian murdering Aetius demonstrates how isolated the Emperor had been, as he had to do it alone with a single friend, in Rome (not at the Court in Ravenna), and was faced at once with desertions. Of course, he did not survive it for long. It is however telling that Valentinian III enjoyed a good reputation among the Roman people even up to the 6th century.

The political legacy of Aetius is thus not the saving of the Empire, it is the undermining of Western emperorship. The Emperor was left utterly impotent, and when powerful men longed for influence they now went for the domination of the military offices or barbarian kingship, or a combination thereof: Ricimer, Gundabad, Aegidius, Orestes, Odoaker, Theoderic, Syagrius, Clovis. At max they needed a Western Emperor to work as their puppet: Romulus for Orestes, Glycerius for Gundabad, Olybrius for Ricimer etc.
Even when the Emperor of the East tried to revert this development, he failed (thanks to Genseric, btw.)

That is the real legacy of Aetius.