I will attempt to answer this. Sovereignty IN a state is the subdivisions of that state, Counties, Townships, Cities, Villiages, etc.
Each is seperate in governmental operations such as jurisdiction of police, etc. Possibly some jurisdiction may be concurrent in nature (shared by more than one entity).
For example, in my state, Ohio, we have 2 Counties which have an Executive -Council form of government, the other 86 Counties have a 3 Commissioner form.
If we are speaking of a Sovereign and it's immunity from suits, the STATE has the say in that, by statute, whether it is a Proprietary or Governmental function.
We have what is known as the "Political subdivision tort liability act" that discusses such, in addition to case law on the subject of the 2 types of operations.
Each municipality in Ohio has "Home Rule" authority. This means that even if a law under state statute is a Misdemeanor of the 4th degree, for example, the city can make it an an M-4 or above, this is not a conflict under the Home Rule Amendment, Ohio Constitution, Article 18, sec. 3.
Townships however, can not pass laws, just Resolutions, if I am not mistaken, punishable by fines only, no jail time. If they wish an offense to be punishable by a possible jail sentence, they need to cite the parallel under state law.
The 2 Counties of Council-Executive can however pass Ordinances with possible jail time.
Powers and or Sovereignty are therefore a product of the state, actually.
The STATE itself, although able to legislate for the subdivisions, the opposite is not true for the cities, they can not legislate for the state.
Also, if I am not mistaken, OHIO, has WAIVED it's sovereign immunity from suit, as long as the claim is valid, this I believe would be filed in the Ohio Court of Claims, (no, not small claims).