How can one balance the necessity of accompanying non-committed colleagues with religious adherence, while making them helpful in obedience?

A person is not obligated to accompany those whose companionship brings no benefit. As for those you must interact with at work, mix with them as needed, and seek out righteous friends who will help you obey Allah. As for work friends and the like, interact with them only as necessary, without excess. Try to advise them, and if they do not respond, reduce your interaction with them, for solitude is better than a bad companion.