If three years works for you and your customers, then it certainly can be used.
You ask specifically about revised procedures and quality manual? there is no requirement to keep copies of those at all. You can if you wish. (I just keep a database that shows date revised and a summary of the changes, that doesn't make any other thing wrong) One item I saw that made me smile....Obsolete documents=lifetime. What lifetime? If it is obsolete, its lifetime is virtually ended, right? You have several "lifetime" retention times that don't really explain what a lifetime is, lifetime of your product (expected useful lifetime), lifetime of your plant?
Just remember that you should make your system fit your needs and any requirements that have been given to you by your customers or any legal/regulatory requirements.