Issues with appending

Hello, I’m a very new blender user. I have, for example, a complex room in a .blend file that I want to add a model to and start posing that model, from a separate .blend file, in the room scene. I know that to do this, I have to append the character model to the file with the room in it. My issue is that when I’m appending the object (and its rig and other accessories, etc.) to the .blend with the room, it appends everything over as its own, separate object, with none of the original collections, which just absolutely blows up the outliner. How do I go about appending the model exactly how it was in it’s own .blend file (with its options, collections, etc porting over exactly the same)? This isn’t an issue with simple things and a few objects, but it gets to be a real issue with complex rooms and characters.
Any help is appreciated, thanks!

Is it possible to append an entire collection instead? Rather than going to the actual objects when selecting things to append, you will see that there are other “folders” to take things from. See this picture:

If you want an entire collection and everything within it, in that hierarchy, then it might work to append the collection. (See second folder in the picture)

In my example, I have five collections:

Appending one of them works like this:
image