Promoting healthy conflict (which is about the issues) is essential for getting the best ideas on the table, challenging assumptions and getting buy-in. Here's a short HBR article that shows one way of increasing your team's ability to deal with it: https://hbr.org/2019/03/an-exercise-to-help-your-team-feel-more-comfortable-with-conflict
However, before healthy conflict can take place, there must be trust on the team. This is the first step on 'The 5 Behaviours' ladder which we use extensively to help teams at all levels become more effective (see the 'Tools' page on our website for more information).