That can be handled with hashtables.
I speak about systems where you combine few units with different ID under same point value.
Example:
Footman and Knight have different unit type ID, but you can set their PV to 1
Grunt and Rifer have different unit type ID, but you can set their PV to 2
This way you can create group of units with same point value and so on.
Hashtables can work here as well.
But if you work with 5 different systems in background that use all kind of custom numbers and things saved within different hashtables, this is cool way to link all them together.
Now this can be horrible example, but I would need to paste 50+ long word pages of code to show you real example (from Shadows of the Past map, again, for example).