AIUI, the lacrosse equivalent of the Six Nations is the World Lacrosse Championship, where the Iroquois fielded a team - as did the Scots:

https://en.wikipedia.org/wiki/2018_World_Lacrosse_Championsh...

The Iroquois beat the Scots 14–7.

The World Games is sort of the Olympics' El Ocho - a competition between national teams in sports that aren't quite big enough to be in the Olympics. As such, they follow the Olympics' principles for recognising entrants, which require entrants to be states, rather than just nations (mostly [1]). Hence, neither the Iroquois nor the Scots get to enter a team of their own (in Olympic rugby sevens, Scots are part of the GB team).

So, the Iroquois don't get to enter a team in the World Games, despite inventing the sport. The Scots don't get to enter a golf team for the Olympics either.

[1] https://en.wikipedia.org/wiki/Independent_Olympians_at_the_O...

[1] https://en.wikipedia.org/wiki/Chinese_Taipei_at_the_Olympics

This is a fantastic point. The commentary about the passports is really a sideshow: if other nations that are part of a larger state are allowed to participate, so should the Iroquois.