But that's the thing isn't it? They died because of their connection to Mando so while "networking" helped him it really didn't help them.
I don't see what this has to do with the question of Cobb Vanth becoming a Mandalorian.Din didn't question that a Mandalorian would be alone on Tatooine. He simply questioned that he didn't already know of a Mandalorian on Tatooine despite spending time there.
Let's put this another way, when you said the Marshall would become an actual Mandalorian, what did you mean exactly by that? What would change in his life in positive and in negative?