The key is to find a model that works for your company, in your industry, and realize that there have to be people working in specific roles being led by one leader--not necessarily by multiple managers.
Consulting businesses thrive on finding individuals who develop great relationships with clients. To find those people, however, you need to be clear on your own organizational structure and in creating a company culture that attracts and retains those individuals.
Developing ownership's roles and goals is a start to creating that culture.
All the best.