One country in my setting is essentially a bunch of micronations similar to German states during the Kleinstaaterei period - a set of hyper-fragmented, heavily (if non-ethnically) Balkanized, near-sovereign states that make up a whole. Basically, they put on a trenchcoat and pretended to be a country, up until one of the smallest ones found a cache of alien technology on the outskirts of a perpetual hurricane, giving them a significant boost over their neighbors in terms of things such as "fertilizer", "utilization of electricity", and "smokeless powder".
They expanded outwards, but, obviously, they couldn't take over the larger mini-nations with technology alone. Therefore, they traded their secrets for political alliances, and steadily grew to be the predominant power in the region, which ensured that there wasn't really a disparity in tech level in it.
Eventually, managing an empire spanning the entire Iberian Peninsula, France, and a fair portion of Northern Africa turned out to be logistically taxing - not to mention the fact that the ~50% of the country they brought into the fold by force isn't too happy with that - so they came up the following: each state was allowed to self-govern as its own mostly-sovereign nation, provided that they paid taxes and gave the central government control over their military forces in times of war. Moreover, provided that the entire country is not at war, each individual mini-state is allowed to go to war against each other one if given permission by the central government. This means that states that step out of line are pounced upon and assimilated by larger ones.
Eventually, this got out of hand once a significant portion of the central government was assassinated with a thermobaric weapon. Unfortunately, every micro-country had some form of nuclear weapon by that point (they had actually shared with one another - mutual defense against invasions), and without a central authority to tell anyone who's who, nuclear warlordism broke out.
In terms of historical precedent (barring, of course, the alien technology and nuclear war), is this realistically plausible?