Hi @erron
Without seeing any code it's kind of difficult to throw some ideas, although it seems to me that you may consider encapsulating your that logic inside a Trait that you can then use on those Models that need to apply this very same validation.
Just in case, here you have an example of implementing a Trait to reuse code for validating and storing uploaded files: https://www.develodesign.co.uk/news/laravel-traits-what-are-traits-and-how-to-create-a-laravel-trait/
Hope this helps