I pray that we will mature to the point where we can discern when someone is functioning outside of the realm of influence that the Father has marked off for them and we don't tolerate it. That's my prayer. Make a plan before your group is confronted with this scenario. When someone new visits your group and violates these boundaries, it will be easier to speak up about it if you've already discussed it. There will always be doctrinal differences and that's not what I'm talking about here.
Doctrinal differences are healthy in any group.
They keep us sharp as iron sharpens iron. We all see in part. For instance, your group may set a boundary that the women should go according to their own conscience regarding headcoverings. They would be trying to insist that you walk according to their revelation, instead of what the Lord has shown you individually. This would be a boundary violation.