Warning: Risk of fire! Basically every consumer - even the smallest - should be protected. Even small consumers, with a current consumption of only a few milliamps, can be the reason for short circuits and cables catching fire after power is supplied to them. In case of bad cable management in the vicinity of flammable materials, even a thin cable (for example 2 x 0.5 mm²) can cause a huge fire hazard after a short circuit.
A breakdown of the consumer in several circuits and a corresponding hedging is useful and makes sense in any case. If a consumer / circuit shuts off due to a short circuit or similar, you are not completely "in the dark" and board operations can still be maintained.
Make sure when installing the fuses are easily accessible - it makes no sense to install a flying fuse to a power supply and then hide it behind the wall or ceiling.
Circuit breakers versus fuses - both are good and useful. High current cables, such as windlasses and bow thrusters can be well equipped with fuses. For smaller consumers, circuit breakers are better. Ultimately it is a question of the money and the price, for deciding which type you choose. When using fuses, a number of spare fuses on board should always be available and ready to use in any case.