If they are not hub hosted you'll have to get them yourself.
There's plenty of content that is packaged poorly, showing dependencies that are either not needed or have a minimal use on the asset. Personally, I would avoid anything that has more than 50 dependencies unless you know they are needed for sure, and have several non-hub dependencies. Of course, payed content will not be hub hosted, at least in its entirety, but the content creator should provide you with instructions for what you need.