merging lists

Dear all,

I have a scenario below. In case I want to merge 2 lists.

By using 'list replace' we know exactly where the new items would go because we use the original item (index)

But what about if the original list unknown, just like shown below: only item lists A and B.

In my GH Definition I could easy 'insert' B into A, but it’s not a good idea coz it’s done by hand... (Imaging when we have list-length by 100...)

I know we could use cull-pattern +weave to merge them. But we use them only when the list-item contains specified rhythms (pattern).

Does anyone know an elegant solution to merge lists (which has not any rhythms (pattern)) and sort/ rearrange them as C?