This alt history starts in ep 6 where Zhu le does not pretend to switch sides in this timeline and when Varrick creates the bomb, bolin is not there to earth bend them out, hense killing Varrick and Zhu le, this prevents Zhu le from leaking the war plans later in the season giving Kuvira and the Earthen state a upper hand in the upcomimg war, along with more focus on proper centralization of the Nation would take place in order to conscript more soldiers and get more industry for power armor (power armor is canon to lore). During the same ep of ep 6 during the battle of Zhou Fu where she captures the people or whatever, they are shipped off to the reformed prison camp of lake Laogai and the suspended platforms are more complex so earth benders cant see the guards as well, along with heightened security because its a important world leader(s), the plan to free them would ether cost much more effort and time, or fail, along with this would stop them from finding the spirit canon hense limiting republic citys info even more Lastly is the battle itself against a under prepared republic city, now Kuvira wins this by the president announcing surrender on live broadcast, but before hand she sends in the Di Le to capture Korra snd friends in a night time stealth attack, this takes Korra off the playing field and allows the annexation of the united republic This is roughly how it could be done, also during this time Kuvira gets but tons if researchers from across the Earthen state to do research, and with spirit vine energy being much more of a thing, guns and artillery and tanks and anti-tank and all of that yummy cold war era stuff starts to be invented for the next years, along with more centralization
