One of the hardest things for a team to do is to field the same team at every race or regatta. Inevitably someone cannot make the event and the team has to adapt with new crew. This is a reality of life that just about every team has to adapt to.
As a coach I recognize this fully and have formulated team position charts for different types of boats so that the team has a blueprint on how to plug in someone new as seamlessly as possible. The most challenging scenario very often is on bigger boats where there are more team members and very often more complexity than smaller boats' teams experience.