It’s important to take into consideration that this idea of a team is not only to compare between two people, but with all team members.
In exemple, if I want to complete my city with my friend, let’s say 5 people, we would see the combined 5 lifemaps creating the Team Lifemap.
Like @steveamor12 said, when you watch the Team Lifemap, our own lifemap should be at the top and the others under it. I suggest to order them by the less number of street completed first, like that it’s easier to see the work of the members that walk less.
I say that because in my case I walk a lot, but not all my friend will walk as much as me.