I have built a Wordpress site and the site owner is inviting another person to join. The site is a referral site and my take on this is that two people adding content will help with developing the site as a resource and also improve SEO. The site has the potential for a number of people to join and that can only improve things by increasing the range in the service offered. But now I'm thinking how the two participants might share any referrals.

The site will be a referral site for two professionals but one will own it and retain editorial control
Each of them provides a similar service with a different emphasis
Both will develop their own practice in traditional ways eg word of mouth, repeat business
The site gives the impression of a single practice but each practitioner will be independent

I will put a selection on the referral form that will enable enquirers to select a person but I am sure some will get through with no choice.

I've never done this before and would welcome any pointers and advice around the area of co-contributors to a site in a loose partnership