just after Adrianople something of that sort happened.
Theodosius had basically a bad situation and with not enough men in the army, thus had to come to an agreement with the same goths that had devastated Thrace.
Several would-be-usurpers could be beaten only thanks to barbarian warriors fighting in the army and/or as mercenaries.
But we shouldn't overstress the barbarian character of those: most of them (all of them in in the upper social strata) were culturally assimilated, spoke greek or latin and were christians.
During his Arcadius' reign, a 'xenophobic' current emerged in the politic of the ERE, and most of the goths were gradually relocated westrads and westwards, until they arrivet in the WRE (which really was not able to manage them).
Anyway, this new course, too should not be overstressed. Huns, for example, remained a source of mercenaries for the ERE for centuries