Hello,
For your first requirement of relaying approval, you can do it by creating 2 approval status columns, one for Ann and the other for Ben. Then in the second workflow which should be created in sharepoint designer, set it to be triggered when item updated, the conditions should be approval status (for Ann) equals Approved and modified by equals Ann.
For your second requirement of operate workflow on different versions of document, I don’t think it is possible through out-of-the-box ways. You’d better copy the old versions as the other documents to let it work.
Regards,
Jerry
Xing-Bing Yu