We usually try to assign users in Org Strctures either by creating a new postion and assigning the user id to it (or) Drag and drop.
There is one more way by which you can assing the user which is there in Org id A to Org id B. This is a standard procedure and you can follow it
There is one more way by which you can assing the user which is there in Org id A to Org id B. This is a standard procedure and you can follow it