First of all there is a traiangulation relationship with all those individuals in a cluster. The little colored boxes represent two people who are matches of eachother and match with you createing the triangulation. Now if the amount of shared DNA is very low it is possible that they may not triangulate among theirselves but that isn't essential but what should be there is some cross matching. Like A & B are matches and A and C are matches and C and B are matches. There will be some of that cross matching if you look at their accounts.