The phrase "main role for" is correct and usable in written English.
You can use it to refer to someone's principle purpose or duty in a particular situation or activity. For example, "The main role for the lifeguard is to ensure the safety of the swimmers."
The main role for our senior leaders now is surely to nurture them.
A main role for the computing part of this project would be to handle calculations so that users can focus on qualitative patterns and relationships.
The main role for the student would be to assist with the extraction of microbial DNA from field collected samples from birds.
The main role for the fiber reinforcement is to limit the bulging of the elastomer layers, and is the dominant parameter affecting the vertical stiffness.
"It's any kind of art," says German pioneer Hans Peter Kuhn, "as long as sound plays the main role". For many practitioners, this delicious ambiguity is sound art's greatest strength.
Today, the main role for local-area wireless technology is to connect mobile devices to corporate LANs a job that the existing 802.11b wireless standard was designed to do.
Fury Road, on the other hand, reserves its main roles for white women.
I think one of the main roles for a leader is to get as many opinions as possible on the table.
This paper illustrates three main roles for the firm in developing a user network: creating lead-users, organising directed applications development and facilitating user-to-user interaction.
In fact, although it is still out of reach for the majority of Indians, the Indian Grand Prix ended up fulfilling one of its main roles for the wealthy: As a place for business-to-business activity, it instantly became one of the most popular for the corporate team sponsors, potential sponsors and their guests to meet.
The next lemma and theorem play main roles for obtaining a fixed point in the Ptolemy metric spaces.
