The biggest difference is that an SPA is the sale of all shares, and an APA is the sale of selected assets. Therefore, they are both different transactions and have different procedures.
Asset management is the process of planning and controlling the acquisition, operation, maintenance, renewal, and disposal of organizational assets. This process improves the delivery potential of assets and minimizes the costs and risks involved.
The Procurement process provides a basic Asset Management lifecycle for procuring assets. It uses related actions on a corresponding Configuration Management process, so you need to ensure that the default process for each CI type you want to use with this process includes these actions.