This is quibbling. The sole issue is national sovereignty of a individual nation-states, which the USA does not have over its member-states-- as the federal government claims. Nothing else matters.
You’re confusing centralization, with national sovereignty– which the CSA states never ceded to the CSA Union, nor did did the CSA allege; indeed, that was the sole issue between the two Union, i.e. the USA claimed that the states formed a single nation-state, while the CSA states claimed they were always separate nation-states.
That’s what it was ALL about. If the North admitted that the truth, that the states were sovereign nation-states, then there could have been no war; however charlatans fabricated many arguments to deny this fact under color of law, from Jackson to Lincoln.
Separate nation-states can form federal republics which can be as centralized as they please, without forfeiting their status as separate nation-states; this can only be lost if they expressly manifest such an act; and the American states never did that.
That’s the confusion which plagues most people today, in claiming that USA’s common military, currency, whatever, made the states into a single nation-state, by implication… when all that is pure bunk. It doesn’t work that way, for reasons I just stated.
The Euro, the UN army, etc. did not make those nation-states into a single nation-state-- but Hitler, Hussein and Hirohito * claimed* this in their various conquests, with the same legal validity as Lincoln-- i.e. none. Again, it can only happen by* express action,* since a nation-state is its own supreme ruler by law, in terms of judging legal intent. Thus, nothing can be *left *to judgment in such a treaty which joins two or more nation-states as a single one.