That's right! Here's a full explanation for anyone not familiar with JFDLC:
Exploration Continued Expanded (ExCE), one component of JFDLC, introduces attrition on some terrains, including desert. If you're playing with ExCE active, the Nyintiringkupai grants newly trained units immunity to Desert Attrition. This happens in addition to the Survivalism promotion; it doesn't replace it.
There's currently no definitive proof of connection between the languages of the Americas and those of Eurasia— however, there are some theorized connections. The most widely accepted of such theories is that of the Dené-Yeniseian language family, which links the Na-Dené languages of North America to the language of a little-attested Siberian group: the Ket.
I used a workaround (originally written by LastSword) that causes missionaries, when purchased by a player of the appropriate civ, to be replaced with the unique unit.
This does lead to a bug where the purchase menu will just show the default missionary, but from a gameplay perspective everything functions as appropriate— a Ket player will receive a Sening when purchasing a missionary, and anyone else will just receive the default.
I don't know if you take requests but I have a request for a civ that to my knowledge nobody has done before for Civ5, namely the Mixtec(not to be confused with the zapotec, they are very different).
Leader would most likely be Eight Deer Jaguar Claw and the civilization heavily oriented towards Science and conquest(They made war on the Zapotec until they had taken the valley of Oaxaca. The Zapotec eventually struck back and retook some of those cities, because of the crafty Cosijoesa, a Zapotec King.:
Leader: Eight Deer Jaguar Claw
credit to the artist on Deviantart for this image:
Its cool about the Mixtec, the Australian civs are really intriguing too and its interesting because like the Americas there were thousands of tribes and some have written books stating some of them were far more advanced than you'd think.