Anyone have any insight into this? In the TTT glossary, the entry on the Cuno-Inchoroi Wars, mentions Sin'niroiha, a rival to Cujara-Cinmoi who becomes the king of Ishoriol/Ishterebinth through marriage. CC makes peace with S and when the nonmen gather to fight the Inchoroi after the Womb Plague, S leads the nonmen's retreat after CC is killed. As far as I can tell, S is not mentioned anywhere else in the series.
Perhaps Sin'niroiha IS either Nil'giccas or Nin-Ciljiras. But it would be weird if he is N'G because N'G is mentioned later on in the same entry. Anyways, this S person is really formidable having fought to a stalemate with CC and because of his actions in battle.
P.S. Also, reading the Cuno-Inchoroi war entry, I was reminded that CC was killed and his head was not recovered. Bakker loves CC, so maybe we'll get to see CC's reanimated head in TUC. Headless CC reminds me of what happened to the dwarf king in Tolkien in the events that led to the Goblin Wars.