My best guess is that the best models would be the Palestinian Authority (PA) of OTL or the warlord militias of Somalia and Afghanistan.
As of the POD they were still both highly tribal/nation centered, (in that order BTW) which made the organizatoins loose and under constant stress. That's not likely to change for any internal reason but outside threats bring them togther because they will REMEMBER how that was used against them before. But for the most part the external threats are going to be pretty fleeting. Combating alcohol smuggling works for a bit, opposing ISA and Texan agression is a bit better but in the long run they will have to find a leader or system that actually and amincably brings them together or they will end up falling apart. Part and parcel of this is going to be a major internal struggle over the resources of their land because in the end the choice will come down to remain poor and under-strength or turn the "whiteman" ways of exploiting their resources to raise themselves to a point where the other nations must except them as equals.
The Lakota have a bit of an advantage as they can mesh fairly easily with the ex-Canadian "First Nations" but the southwestern Native American tribes have fewer choices and/or opportunities. They also have more internal conflict due to their make up with the struggle between the Navaho, Hopi and Apache nations vying for being the 'main' tribe. There's a book called "The Cyberway" (https://www.amazon.com/Cyber-Way-Alan-Dean-Foster/dp/0441132456) which supposes OTL Native American tribes decide to exploit some of the natural consequences of their supposed legal and offical status within the US to allow foriegn investment and international trade due to being 'nations within a nation' by treaty and agreement. (Even thought that's actually not how it works at all) TTL in Crimsion Skies they ARE their own nations which means they can very much benifit from outside investment and support. But they have to both ALLOW such "help" from outsiders AND find enough unity of purpose and will to not be destroyed or broken by it.
Now keeping in mind that TTL's Arixo as titanium deposits, (well according to the video game) and some other resources it has both a reason and oppotunity to actually accept outside money and equipment and with the right leadership it could turn this into a leapfrog from their 19th century existance to a late 20th one by the 1940s. Meanwhile the Lakota and First Nations can do something similar in the North using timber, oil, coal and gas deposits which they can sell outward and invest inward. By the late 40s and early 50s if "America" has avoided a major internal war they, along with most other American nations could be looking at a properious and stable situation where they are both trading partners and hubs for goods and services which places like Hollywood, Texas and Pacifica will likely have over-exploited.
If they do not find that leader or system however by the late 40s there will likely be open tribal warfare over their internal and external issues. This will lead to an ever harder line against 'outsiders' and their influance/corruption enough so that every decade or so some charismatic leader will rally the tribes into an external campaign to 'reclaim' their heritage or some such resulting in a few victories before external defeat or internal schism brings them back within the borders and into isolationism. In such an outcome there will be cycles of rampent exploitation of the natural resources to pay for upgrading and expanding the air and ground forces equipment and technology followed by slow decay and withdrawel into in-fighting and calls to 'return to our roots'. Such cycles would make our current reservation system and situation look like a paradise in comparision. And the danger here is those resources are going to look mighty tempting to outsiders around the mid-50s and frankly while the Native Americans would put up feirce fight they'd lose without unity just like that did before. Only this time there will be little to stop the 'victors' from full absorbtion or genocide and the Native Americans would fight back with the same fevor. Even if it doesn't go that far they tribes will continually be pushed into more and more marginal land as time goes on.
You can guess which way "I" would go for but either works for story purposes.
Randy
Deleted member 82792
I've started a new thread here:
https://www.alternatehistory.com/forum/threads/modern-crimson-skies.477953/
https://www.alternatehistory.com/forum/threads/modern-crimson-skies.477953/
Consider that in the aftermath of a Imperial reign of Trump, Biden would be seen as probably a Coalition builder, and a symbol of the Democratic Republic government prior to Trump. This period would be similar to the Reconstruction period, with Allen West and Ted Cruz leading rebels in Texas.