A map is always a restriction of information about the real land. A map is a choice of what information to convey. Its up to you to decide what information that is. Whether a map is a good one or not is not by how artistic or colourful it is but whether it conveys the information is claims to show in a clear and concise fashion. And no map will contain every bit of information about everything. If the aim is to show the migratory routes, ocean currents, or elevation then it may not need to show each individual island. Many maps of earth for example show the barrier reefs as a continuous splodge because for most people its boundary and extents are more important than knowing each little bit of it. I think you must ask yourself first what is the important information that needs to be described and then focus on showing that well and not be afraid to reduce the accuracy of other items like exact island shape when it would interfere with showing your primary information.