The thing is, in my campaign it's going to need a few changes:
Orcs are smarter than most humans, and tougher as well. They live in a fortress-country and could hold out for decades under siege.
Their are two kobolds- kobold and technokobold. The average technokobold's intelligence is genius-level for any other race-18-and are inventors. Their armies wielding flamepowder weaponry could decimate most of an army.
Frost dwarf berserkers could heavily damage an army as shock troopers, but the frost dwarves won't win in the long run.
Fire gnome fighters are among the finest in the land, and can probably deal a heavy blow, as can their (neutral) Efreet rulers.
GIANTS: These guys are going to be big players, and the PCs bringing back the council of giants (A representative from each giant race, this practice was wiped out when giants lost most of their intellectuals and reverted to tribes) and bringing the full fist of all the giants- The eldritch, the frost, the fire, the storm, the cloud, the forest, the sun, the mountain, and all those other ones may be key, but their most difficult one-and their best ally, will be the death giants. They may even be able to restore the death giant's souls if they win.