Is there a more dynamic way to target siblings in CSS / SCSS?
There is! You can use :nth-child() with plenty of ways to select children elements of particular wrapper, for example odd or even elements, a range of elements, 3 elements after 4 other elements and repeat.
Check this generator to create a rule and help you visualize what elements will be selected:
https://css-tricks.com/examples/nth-child-tester/
Docs:
https://developer.mozilla.org/en-US/docs/Web/CSS/:nth-child