I mean a more logic situation was if Italy and Germany both pay ESA, and ESA contracts the launch vehicle from Germany but maybe the space station module from I

I mean a more logic situation was if Italy and Germany both pay ESA, and ESA contracts the launch vehicle from Germany but maybe the space station module from Italy. But one project often is to large a part of the budget so instead of doing it per project, the split each project into tiny pieces and hand that to each government. However this is also changing a bit. For Ariane 6 they specifically went away from that and allow industry (Ariane Group) to ignore that to a certain extent.