you can pick any team and just focus her. Full length DM lasts about the same time that most teams take to break a rein barrier. As soon as DM is down, she has the biggest crit box and model in the entire game and weapons that aren’t scary unless you’re right in her face.
meanwhile if you have to spend 100% of the time front lining on DVa you’re not actually doing any of the things she was originally designed to do.