I am fascinated by the similarities .... like how nations formed confederations eg. the Haudenosaunee

Right! Exactly! Three similarities we see over the world –

• Tribal confederacies. The Caledonians in Scotland, various Pashtun confederacies in history, various North American ones.

• Small tribal units and big ones. Among the Mapuche, several lov formed a rehue. Among the Māori, whānau confederated into larger hapū; hapū confederated into larger iwi. Among the Bedawin, several bayt formed a goum.

• Tribal assemblies: þing among the Nordic folk, veche in the Slavic world, sangha in India, becharaa among the Semai, Jirga among the Pashtun

• Community halls or 'third places': the mudhif of the Marsh Arabs, the Toguna of the Dogon, Bulgarian Chitalishte, Caravanserai of the desert people

• Managed commons: the tabu of the Hawai'ians, the hima of the Arabs

• Customary law, often with restorative justice: xeer in Somalia, coutume in France, pashtunwali, Albanian kanun. Law without cops of a Babylon-type centralised state.

So I think it's somewhat valid to generalise that there exists a pattern called 'tribal', and then it's interesting to generalise that to the whole world. Was it historically universal? No of course not, but no other model was either. The Westphalian nation-state emerged and became dominant, I'm imagining what if tribal confederalism became dominant?

Australia

Here's a cool map of Australia: https://i.ibb.co/PWB1Nhy/map-221445.png

I think Australia could be almost fully hunter-gatherer, because of its low population density.

The trickiest bit about Australia is the architecture. There really doesn't seem to be much evidence of indigenous architecture. The book 'Gunyah, Goondie and Wurley: the Aboriginal Architecture of Australia' gives some attempt.

Australia generally had no class distinction: https://d-place.org/parameters/EA066#1/30/153

And no slavery: https://d-place.org/parameters/EA071#1/30/153 , https://d-place.org/parameters/EA070#1/30/153

People are more nomadic than settled: https://d-place.org/parameters/EA030#1/30/153 (This is generally a difference between the world I'm building and the mundane world; a large percentage of people live nomadic lives, including in North America, Central Asia, etc.)

Nomads move about 14 times a year: https://d-place.org/parameters/B013#1/29/169

Move about 100km a year at the coast, 500km inland: https://d-place.org/parameters/B014#3/-29.38/144.14 (The Gidjingali, to give a counterexample, are a sedentary people, probably because there's good fishing there)

No money: https://d-place.org/parameters/B033#1/29/169 (This is a major point about the world I'm building; there's no money. There's an economic system of duties and perks.)

Possum cloaks: https://aiatsis.gov.au/explore/possum-skin-cloak

Bush tucker: https://en.wikipedia.org/wiki/Bush_tucker

So my version of Australia is mostly nomadic hunter-gatherers, but they have solar panels, batteries, vehicles. When they go on their huntgather walks, they use vehicles like this – in actual fact they made it work with just walking (no wheels), so with a vehicle like that it should work and be easier. Another thing that would be important around the world I'm building, but especially in Australia is airships: they're solarpunk, use very little energy, don't require roads.

South America

South America divides broadly into three cultural zones: the Andes where’ve got groups like the Inca, the Amazon where you’ve got groups like the Tupí-Guaraní, and the Southern Cone where you’ve got groups like the Mapuche. Here’s the broad map

Here are two more detailed maps: 1, 2

Generally no class distinction in the Amazon: https://d-place.org/parameters/EA066#1/30/153

Southern Cone people include people of the canoe, the Mapuche with their trademark hats with brims, and people whose lives are tied to llama-alpaca herds.

The Incans had a welfare state and sophisticated agriculture, with lots of root crops: obviously the potato, also other lesser known ones like maca.

Caribbean

Taíno + Arawak + Carib people. They eat the hutie. Mangroves are an important ecosystem

North America

Map of broad cultural areas.

• In the desert southwest, you have people of the pueblo, who live in large stone cities. Chaco Canyon is a pueblo-city corresponding to the conurbation of mundane Vegas, Phoenix, etc. They did lots of underground architecture; in my world you would descend into a stone passage with those vibes to catch the subway.
• On the plains are people of the buffalo. This is the best example of my point that thriving culture requires thriving ecosystems. They are nomadic, following the herds. They can use motorvehicles for this. The ‘chickee’ is a waystation on the plains, and they use it to recharge vehicle batteries, etc. A truck stop, basically. The tribal confederacy is responsible for its upkeep.
• Inuit culture in the far north
• South of that, subarctic people like the Cree, where it’s still cold enough to wear a lot of fur.
• Northwest coastal people such as the Tlingit and Salish are characterised by plankhouses and totem poles.
• East of them (but not as far east as the buffalo-folk) you find sedentary people like the Mandan, Hidatsa, and Arikara. Their agriculture is based on the Three Sisters. Their architecture is earth-covered.
• The area around the Great Lakes has people like the Haudenosaunee. They are sedentary rather than nomadic. Saukenuk is a major city. Their architecture is bark-clad longhouses (the size of apartment-buidlings, in my world).
• The mound-builder culture is the culture of the southeast. In the hot parts (Florida) they go about in loincloths. Cahokia is their major city; it’s interesting to think about a 21st-century Cahokia, where city-blocks are mounds, and there are bicycle-lanes between the mounds, and you enter a earth-and-wood tunnel in a mound to catch the subway.
• In California, the acorn is the staple food. You can think of Californian food as fishing+acorns+insects. A weird 1951 paper (doi:10.1525/aa.1951.53.4.02a00050) talks about how Californians had the Protestant work ethic. Here’s a beautiful map of California

Generally no class distinction in North America: https://d-place.org/parameters/EA066#1/30/153

North America is not the population centre of the Americas; central America is: https://en.wikipedia.org/wiki/Population_history_of_Indigenous_peoples_of_the_Americas

Firstly, thanks for engaging!

I feel like, at first, you need to address a kind of Columbian Exchange. The easiest way to start seems to be Viking contact with the Americas being more in depth, transferring Iron Age technology along with some beasts of burden.

So the horse is native to America. "By about 15,000 years ago, Equus ferus was a widespread holarctic species. Horse bones from this time period, the late Pleistocene, are found in Europe, Eurasia, Beringia, and North America". One of the tweaks I'm making in the alternate history is that the American horse never became extinct. (In fact, it became extinct in America, was domesticated in Eurasia, and then the domestic version was reintroduced to America.)

There may also need variance in the role of the state and religion in managing the various technae.

This is a world without the Westphalian nation-state. Yknow the way in the boring world, the Westphalian nation-state became the main thing? That didn't happen here. It is still the tribe. And tribes confederated in a way I didn't detail yet. As for religion: that's also different, mostly animist or pagan, never Abrahamic.