You are right, early Blender didn’t have collections, it had those little squares or layers on the bottom and those were all the “collections” you had to work with. As you say, you can organize the feathers nowadays in that way you describe or any other way you feel would work best, there’s no right or wrong. I bet you appreciate collections now more than ever. You always ended up using all the layers and you’re like dangs it, I need more squares.
And yes, on computer efficiency, it is absolutely much better to have linked duplicates, as long as it is a possibility, since of course if you need variation you can’t achieve that with links duplicates. But for something that has a lot of repetitiveness, you can get away with a couple of unique objects and distribute them in a way where the repetitiveness is hidden.
