This concerns AOR units that can be recruited from city buildings, not Romanized auxiliary units. I think AOR units are one of DeI's most interesting features since it keeps things fresh while conquering the map, and can even give incentive to conquer particular cities. Sadly a good number of them are not viable. Their morale comparatively makes little sense when you look at their training, role and required tier of city building. For example, compare these:
Skiritai Swordsmen
Sparta, Tier 1, morale 55
Spartan (Thorax) Hoplites
Sparta, Tier 2, morale 50
Macedonian Pikemen
Pella, Tier 3, morale 35
The Spartan hoplites should probably have a better morale than the Skiritai. But especially the pikemen are disappointing here, since a morale of 35 makes them terrible in their role of holding a battle line. They also require Pella at tier 3 city building, which is a pretty significant investment in terms of research, building time, and required food before you're able to access them. These units could be very interesting to Greek factions that don't have pikemen in their standard roster, like Rhodos and the 4 Greek colony factions, giving an incentive to conquer Greece. But not with a morale of 35.
Now look at this:
Rhodian Slingers
Rhodos, Tier 2, morale 30
Rhodian Mercenary Slingers
morale 40
Sure the AOR units are cheaper in upkeep than the Mercenaries, but with a morale of 30 the AOR units are very prone to flee after taking only modest damage. Considering you need to conquer Rhodos to access the AOR while the mercenaries are readily available all over Greece to anyone, does this make sense? Currently I'd always take the mercenaries over the AOR due to morale.
Taurisci Axemen
Rome, Tier 2, morale 50
Italian Swordsmen
Rome, Tier 3, morale 35
Who would ever recruit Italian Swordsmen with a morale of 35 when you're at the stage in the game where you have Rome at tier 3? It's such a shame, because units like these are practically out of the game.
I'm currenty creating a submod to increase the morale of some AOR units, but it would be much better for compatability if they could be rebalanced in the main mod. The required city tier could also benefit from review in some cases. I realise it could be a lot of work, but perhaps people can provide feedback if they know of any AOR units that are currently not viable.