"In order to achieve a higher standard of validation, birth or baptismal records are needed since they will generally contain an actual date of birth, something which is unfortunately lacking in almost all censuses or marriage records."

Agreed! However, it's worth noting that, at least for US men, we have mid-life documentation that frequently gives a full date of birth in the form of World War I and/or World War II draft registration cards. Quite sad that the World Wars and US participation in them at least ended up being useful for subsequent extreme age validation.