Best Multi-action, Multi animation workflow for keeping organised within the one blend file?

So I have a bunch of actions that need to occur at once, but in different combinations and in the same file.

Ideally, I could just add all the actions I want into one collection, and that collection could be swapped in and out, the same easy, convenient way as an action.

In modo of all examples, this is far more flexible, so I’m used to easier workflow. You simply assign all ‘actors’ you want to associate with the one action, so much more intuitive, where’s the alternative to that? Do I really have to have each take by in a separate blender file? I need to jump between editing multiple things at once, and that’s not practical to me, but I can embrace the best methods.

What workflows make this the most well organised and practical to work with?