How does this AoR system work?

[Evilbookworm]

Is it that you can only recruit certain units in certain areas (like rome did with the elephants, or the various theatres in empire) or something else? I only ask because I understand the RR turn off option is bugged, so I either need to learn the system, or find some way of removing it, since I generally detest such things, yes they're realistic, but I like choosing a factions' roster and going with it.

Thanks

[bɑne]

Let me suggest a shortcut then:
No Waiting for 6.3 v1.2