[PvK]

Sidestepping to reality, with IW as the dev team, it depends on whether or not they already have a way to categorize units into appropriate/compatible types. I can't think of any evidence that they have any such categories - my guess is the existing "themed" mercenaries and independent province attacks and reinforcements are all hard-coded.

Even so, it seems to me the hard part would not be adding a (object-oriented or not) method for categorizing units itself, but creating one that works for all unit types, assuming none already exists.

It seems like the tactical AI could also benefit from a method which knows to separate units with dangerous auras from units without invulnerability to them.

Anyway, recording units and putting them in Groups by compatible type for later use sounds pretty straightforward to me... though I don't know what data structure they use. If it's a massive array with all kinds of ancient spaghetti attached, maybe it would be a pain.

Most we can do about such code details is speculate, though. I mentioned the idea because it sounded like the _main_ obstacle was lack of a fun idea for what to do about disbanding units, so I thought I'd mention what sounded fun to me.

PvK