Many Planets

Avalon, colonized from Terra and Ythri, resists Terran Imperial annexation and remains in the Domain of Ythri.

Freehold, colonized from Terra and Aruli, resists the Empire until it gains a charter of self-determination.

Ansa and Aeneas resist Imperial annexation but later come to accept incorporation into the Empire.

Alfzar remains neutral despite extreme provocation from both Terra and Merseia.

Flandry keeps Irumclaw in the Empire, neutralizes Talwin as a Merseian base, defeats an Aenean rebellion, subverts Scotia, suppresses Brae, liberates Unan Besar and Vixen and counteracts Merseian subversion on Nyanza and Altai.

Dennitza, misled by Merseia, nearly secedes from the Empire but then retaliates against Merseian Intelligence on Chereion.

Hermes loses stewardship of Mirkheim under the first Molitor and becomes the centre of a potential coup under the third.

Starkadians are resettled on Imhotep in the Patrician System. Daedalus, also in the Patrican System, becomes the centre of an attempted coup, suppressed not be Flandry but by his daughter and her companions.

Atheia, Kraken and Freehold provide some continuity of civilization after the Fall of the Empire.

This is not a comprehensive list but it does show twenty six planets interacting with each other in various ways. The interactions show that the Terran Empire is neither simply good nor simply bad but can be either, as in real history.