The phrase "are mostly dominated" is correct and usable in written English.
It can be used to describe a situation where one group or element has a significant influence or control over another, often in a comparative context.
Example: "In the current market, small businesses are mostly dominated by larger corporations, making it difficult for them to compete."
Alternatives: "are primarily controlled" or "are largely influenced".
The industries where the government expects the most employment growth between now and 2022, such as health care and hospitality, are mostly dominated by women.
Primary schools are mostly dominated by one of these communities, so often the first time young people of different races mix is at secondary school.
These functional constituencies, as they are known, are mostly dominated by people who have connections to mainland China, many of whom have investments there; they tend to choose pro-Beijing lawmakers.
These are mostly dominated by compounds extracted from traditional Chinese herbs and medicines.
For example, remnant natural land hardly exists in rural landscapes in Europe, which are mostly dominated by cultural landscapes.
This has been related to the complex sedimentological characteristics of rock avalanche dams which are mostly dominated by fragmented and pulverized materials.
That's true of the discourse around energy and climate, which is mostly dominated by business stakeholders and policymakers.
The jurisprudence blotter had been mostly dominated by the N.F.L., the latest coming from a Raiders player arrested in Hawaii for assault.
The dining scene in Florence is mostly dominated by well-established trattorias, either tucked away in neighborhoods far from the city center and frequented by locals or situated in the heart of town and overrun with tourists.
Indonesia's president, Abdurrahman Wahid, seems to be penned in by public opinion, which is mostly dominated by anxieties that interfering foreigners are determined to see this vast archipelago of a country broken up.In this section In the hands of the militia Mahathir's last waltz?
Lithology is mostly dominated by fine sandstones.
