I work in a matrix team where we look after functions but across multiple projects. Certain people in the team focus on specific projects but what try to maintain is the communication within our team for issues across the various projects as more often than not, we have common or similar issues and if someone has a resolution, it may help on other projects too. It's also useful as a lessons-learned sharing so that if others face something similar in the future, they have documents to refer back to. So make sure that even if you have people working on multiple projects, they talk to each other and share best practices etc