Yes and no. Once you've got some practice under your belt, you'll be able to decide what the ownership structures will look like ahead of time. You'll either av

Yes and no. Once you've got some practice under your belt, you'll be able to decide what the ownership structures will look like ahead of time. You'll either avoid circular ownership entirely, or you'll decide ahead of time that you're just going to have to bite the bullet and use runtime bookkeeping of some kind (Rc/Arc/etc). A lot of this is domain-specific knowledge though; if you've gotten really good at writing a game using ECS then the specifics of that might not help you much if you start writing a line of business app or a web page. The ownership and borrowing rules are the same though, so it's not a complete loss.