Lots of men shared the same or nearly the same name. Sometimes records of two or more soldiers were placed in one file; frequently the same man received more than one service file, as in this case. That's because 5th Alabama Regiment and Battalion has an identical prefix (5th Alabama), and many records are simply marked 5th Alabama.
Pension records are designed to include only a brief statement of service. If your primary interest is post-war residence and (possibily) family connections, the service file will not interest you.