The phrase "highly assimilated" is correct and usable in written English.
It can be used to describe individuals or groups that have adopted the cultural norms and practices of another group to a significant extent.
Example: "The community has become highly assimilated, adopting the language and customs of the dominant culture."
Alternatives: "deeply integrated" or "thoroughly absorbed."
Von Neumann grew up in an affluent, highly assimilated Jewish family.
It is highly assimilated, with many interfaith families; Judaism is treated more as a culture than a religion.
The highly assimilated Zsolt felt no solidarity with other Jews, least of all those who were Orthodox.
Highly assimilated with Turkish culture, Istanbul's Jews are nonetheless bound together by powerful and often invisible ties.
(Unlike Eli Wiesel, Levi — a highly assimilated Jew — never quarrels with God, in whom he did not believe even as a young man).
This was the conclusion that turned Theodor Herzl, a highly assimilated Viennese journalist who barely observed Jewish customs, into the founder of modern Zionism.
If you purely feed your fish with pellets, water lettuce is highly needed to assimilate nitrogenous wastes; in semi-intensive systems, duckweed is raised rather than water lettuce for food and nitrogen assimilation but duckweed is 3.3 times less efficient at absorbing nitrogen, thus requiring more surface cover area for a certain amount of nitrogenous waste.
"I did not really know that Felix would be able to lead the project," says Markram. "He seemed highly organised, [and] very quickly assimilated the project...
Some people might find it difficult to assimilate Lesser's highly personalized readings as easily as Lesser assimilated her own texts.
At lobby level, clear glass invites westward plaza views (sky, trees, sister towers, somber memorial pools)—assimilated by a monolith reception wall of highly-polished black Swedish granite.
Both champion highly original artists who achieved some measure of fame without being assimilated into the mainstream.
