Recurring And One-Off Characters

Poul Anderson's History of Technic Civilization features many recurring characters:

Nicholas van Rijn employs a three-, later four-, member trader team, has a persistent opponent and meets the Grand Duchess of Hermes twice;

Dominic Flandry has a superior, a wife, a servant, a friend in the Diplomatic Service, two regular opponents and acquaintances made on Starkad.

There are also important characters who appear only once, like:

Manuel Argos;
Christopher Holm;
Roan Tom;
Daven Laure;
Basil Donovan.

And what do we think of Earl Basil Donovan as a hero? After his planet has been conquered, he gets drunk and starts a riot that gets some of his followers killed. Sam Olman is bayoneted in the stomach. Because of Donovan's infatuation with the demonstrably untrustworthy Arzunian Valduma, he not only withholds information from the Imperials but even gives them advice that wrecks their spaceship and kills half its crew. He agrees to lead the survivors into a trap where they will be telekinetically chained, even though the Arzunians with a slave crew in another captured ship will at last threaten the galaxy.

He changes his mind and warns the Imperials at the last moment maybe because he has become involved with their commander. Anderson's central characters are certainly not cast from a single mold.