How do I add and delete units from a nation?

[Endoperez]

Originally Posted by Epaminondas

Also, is it the case that I don't get the special effects of an armor if I give them to non-commander units? For instance, I gave Myrmidons Fire Plate, but I don't see the fire resistance applied on the unit description screen.

As Edratman said, the ability isn't granted. EA Caelum Eagle Kings have Fire Plates, so you can compare to them.

As Myrmidons are units, you can give them 50% fire resistance. They'll keep it even if their armor is destroyed or they're made commanders and equipped with different armor, but those are special cases and not that important, really.

[Epaminondas]

Got it.

Another one: How do I get move a nation out of an era? For instance, I only play EA, and I want to remove the EA water nations out of the era, given that I don't like playing with water maps.