Sometimes I wish that job titles could be eliminated when teams start using scrum. No more backend developers, frontend developers, UX designers, business analysts, QA testers, and certainly no leads of anything--they are all product developers. Each team member is a person with certain skills. Cross-functional teams are composed of people who have the skills needed to develop the product.
Don't think about what roles are needed on a team--think about what skills are needed. Focus on the people. Otherwise it's too easy to created bloated teams because each role appears to be needed.