How do organizations of vastly different size collaborate in order to achieve a common goal? While this poses less of a problem when the network is orchestrated by a classic lead firm, in networks exhibiting a shared governance mode, where leadership responsibilities are more or less equally distributed, size differentials present a critical management challenge. In this paper, we contribute to the literature on coordination in and of interorganizational arrangements by emphasizing the so far largely neglected role of size for managing close collaborative relationships. We study the case of Apprenticeship Network, a network that originally consisted of seven small and medium-sized enterprises, but which then accepted a very large multinational firm as a new member. By unpacking how the network coordinated its endeavour over time to achieve accountability, predictability and a common understanding as critical conditions for effective coordination, we explore how coordination effectiveness may deteriorate and result in the failure of the collaborative effort. We pay special attention to the role of size in these processes, and we theorize how the strategic front and back-staging of agreed-upon rules and norms facilitates the formation, maintenance and deletion of a tie, thus producing important network dynamics.