Dacians importance in Roman Army

[Epictetus]

I think it is notable that at least one eminent historian implied that the annexation of Dacia was a mistake.

The Scythian hordes, which, towards the east, bordered on the new settlements of the Goths, presented nothing to their arms, except the doubtful chance of an unprofitable victory. But the prospect of the Roman territories was far more alluring; and the fields of Dacia were covered with rich harvests, sown by the hands of an industrious, and exposed to be gathered by those of a warlike, people. It is probable that the conquests of Trajan, maintained by its successors less for any real advantage than for ideal dignity, had contributed to weaken the empire on that side. The new and unsettled province of Dacia was neither strong enough to resist, nor rich enough to satiate, the rapaciousness of the barbarians.

Edward Gibbon, X.