That's exactly why we created Stem! We understand that collaboration is a huge part of the creative process, so our platform makes it easy to split earnings and share data between multiple shareholders. Collaborators are indicated in the upload flow.
Each person who is added as a shareholder on a release will need to create their own Stem account and accept their splits in the platform before content gets distributed. When earnings and data come in, we will visualize them in the platform and account to all shareholders directly.