Realisitc use of auxiliaries

[Visitor13]

Thanks for the help.

Concerning questions number 2 and 3 - Obviously you're describing a more or less stable military situation here, but if the times are desperate? Yes, 'auxilia'
means 'subsidiary', and they're meant to fill gaps in a main army - but what if the gap is legion/full army-sized?

Mind you, I could be contradicting myself here. Pre- 3rd century AD Rome was relatively stable, and such drastic measures would probably not have been needed. And if they weren't needed, they weren't undertaken, so there would be no historical basis for my idea. And a historical basis is what I'm looking for here, really.

So let me rephrase my question - suppose an empire suffers a serious defeat somewhere along the border, there is danger of a major enemy incursion, and the nearest regular army is weeks, if not months away. Would the empire hastily put together a major auxiliary force from the border regions to prepare against the attack? It's risky, I know, but sometimes there's no other way.