Even with a team that is used to each other, there will be some biased towards each others insights. When someone from the team start facilitating a collaborative modelling session, this person won’t be neutral. If we really want to get all the insights we need to make more effective product, we need a more neutral facilitator. While getting some external costs extra money, we might be able to find someone from another team willing to do do it. Althought that persona can also be biased, it is easier to be neutral for someone from outside the team.
Summary of the solution
If we want to model the most effectivly, we need to gain all information and knowledge available that there is. However that sounds easier than it is. Ranking and bias might opress certain perceptions, especially in a group that seems aligned.