This development blurs the definition of the “end of the empire” because if the Germans were commanding a Roman army of Germans, weren’t they essentially controlling Rome? The emperors from Honorius on were puppets.
I also want to mention once again the attitude of the Goths toward Rome, which was essentially respectful. The Goths wanted to settle in more fertile areas south of the Alps and sought peaceful coexistence with the empire. It was only when Rome offended them repeatedly (as in 410 A.D.) that they became more militant. The Goths fought for Rome many more times than they fought against Rome.
The Vandals, of course, are another story – we named wanton destruction after them.