It is a sign of goodwill that other people came to help, and somewhat justifiable because of the common goal of defending against the kitins. Still, you can't deny a matis citizen and Jena worshipper helping the Fyros nation is someone to be wary of as an empire subject (rolewise). Barkers or no Barkers, business of the desert stays in the desert. Ask Icus, would he go help any tribe in the forest?
The tribes doesn't depend to a nation.
Maybe Icus can help a Kamis tribe in lakes, i don't know, all homin are differents and have her own reasons to help or don't help the Empire.
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Tribu Talodi - Fabricant de calumets