There is the idea of how much reality to leaven your fantasy with. Just because astrophysics works a certain way in our reality doesn't mean it has to in your fiction. In fact, if you want an historical anchor/touchstone, astrophysics is a prime example of what shouldn't work in a realistic way. How long did various civilizations think the Sun revolved around the Earth, or that the Sun was actually a god? It's one of the many charming things about Pratchett's Discworld, and it can work in serious fantasy as well.
But if you are writing scifi, it is worth noting that the reason we have reasonable seasons is the moon biasing the Earth's precession around the Sun. Things would be different in a worse way (from the perspective of current lifeforms) if we either didn't have a moon or had many small moons. Also, large moons that revolve around large rocky planets tend to be pushed away over time, as the Moon is being pushed away now, because of gravitational tides associated with the primary's rotation, as the Moonward bulge of the earth slingshots the Moon further out by very tiny distances over time. The Moon used to be very much closer and absolutely huge in the sky.