This is where teams have to make strategic choices, pay attention to their squad, make sure their players are happy, recruit replacements in case of departures, strengthen their squad... Do real management.
Team leaders will have greater responsibility and will have to keep their team afloat and make sure that it is strengthened. Well, maybe I played a bit too much football manager.
I think players should take the responsibility for their choices. Putting the responsibility onto team leaders, who are already putting in a lot of extra effort for the team or onto the tourney admins who (some of them anyway) are putting in a lot of hours each week is not OK.
Sometimes in a team things just dont work out though nobodys fault. having to wait a few weeks before playing in an official for another team is not the end of the world. And is certainly not worth increasing disruption to the tournament or the increasing tehburden on admins.