Can different roles be trained together?
Yes, in parts it is even explicitly sensible. For the fundamentals, the WCAG overview, the four principles and the understanding of why accessibility matters, all roles benefit from a joint session. A shared basic understanding considerably improves later collaboration between design, development and editorial work.
For the in-depth modules, by contrast, we recommend role-specific groups. Developers work on semantic code and ARIA, designers on contrasts, focus states and components, editors on understandable texts, alt texts and correct structure in the CMS. Tools and exercises differ too much here for a joint format.
This combination of a shared foundation and role-specific deepening has proven itself. We plan the right setup with you via training.