A Mixed Colony

Robert Heinlein wrote several short stories with a common future background, then compiled a Time Chart to keep the stories consistent. His editor, John W Campbell, published the Time Chart. Imitating Heinlein, Poul Anderson compiled a (different) Time Chart and set some stories in successive periods of it. Later, Anderson wrote several initially unconnected works that converged to form a third future history. Each installment in this "Technic History" is a substantial novel or short story. They are clearly not written to any formula despite what seems, when analyzed, to be a systematic approach to their subject-matters, e.g.:

Ythri discovered by human explorers;
Ythrians learning from humanity, going into space, later transporting van Rijn;
Gray, later renamed Avalon, explored by Ythrians and human beings;
Avalonian islands colonized by Ythrians and human beings;
an Avalonian continent colonized by Ythrians and human beings;
Avalonian Ythrians and human beings successfully resisting Terran imperialism;
much later, an Avalonian Ythrian spying for Ythri and Terra against a common enemy;
Dominic Flandry predicting that mixed species cultures like Avalon will build fascinating new civilizations.

Philippe Rochefort, a Lieutenant in the Terran Space Navy that attacks Avalon, disapproves of mixed colonies on the grounds that people should be what they are and stand by their own. Be what we are? But what can we become? On Avalon, Christopher Holm becomes, then is, Arinnian of Stormgate Choth - although he does experience some problems in making the transition. Tabitha Falkayn/Hrill, a third generation member of Highsky Choth brought up by Ythrians, has no problem about identifying with Ythri while acknowledging her humanity. She advises Arinnian:

"'...a man or woman who tries to be an Ythrian is a rattlewing.'"
-Poul Anderson, Rise Of The Terran Empire (New York, 2011), p. 502.

"'Can't have it on both wings, son.'" (p. 504)

I dislike Rochefort's idea of standing by your own. This seems to assume a conflict of interests with other groups. His ancestors on Terra suffered because of this attitude. He acknowledges that he is a human supremacist because mankind leads Technic civilization.

"'...my sort of people are the xenosophont's best friend. We simply don't want to imitate him.'" (p. 489)

What sort of people? Rochefort is under no obligation to imitate anyone but, if we makes it his business to disapprove of cultural mixing, then he is not the xenosophont's friend.