John Bonaccorsi, a developer from Tighten, wrote some good ways of structuring model factories in a Laravel app.

Thanks to class-based model factories, our test setup went from being a bloated mess to simple and succinct. The optional fluent methods give us flexibility and make it obvious when we are intentionally changing our world. Should you read this blog post and immediately go and update all of your model factories to be class-based instead? Of course not! But if you begin to notice your tests feeling top heavy, class-based model factories may be the tool to reach for.

https://tighten.co/blog/tidy-up-your-tests-with-class-based-model-factories