Why do you think people left land to the church when they died?

To respect the dead maybe, because leaving land for the Church could let more room for the dead instead of letting the body rot I think.

An informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.