[Sandman]

Re 'Carthage' - how about a Late Era version?

Rathgar: An seafaring empire destroyed by Ermor, with the capital being burned to the ground. The dark magic which cursed Ermor has also affected Rathgar, and the burning dead now seek revenge.

The troops consist of fire-immune (and not cold-immune) undead. Their national undead are less numerous and powerful than Ermor's longdeads, but have a wider variety of weapons available. They have skeletal slingers and (non-banefire) archers, as well as sailing commanders. Their elite units (the burning dead) have fire-shields. Their lesser undead include humanoid beings of ash and smoke.

The undead mages use death and fire (might be too similar to Desert Tombs).

Others:

An 'Inca' nation with strong astral/blood mages and powerful priests. Very good with horrors.

A late-era African nation (Machaka?) with a strong line in domesticated animals - zebra cavalry, armoured war rhinos, enormously powerful war elephants. The 'trampling' nation, in other words.