70-640 TK (Auditing question)

On page 374 the 640 TK (Second edition) says,
"As an example, if you want to monitor changes to the membership of a security-sensitive group such as Domain Admins, you can enable the Audit Directory Service Access policy to audit Success events."
But isn't the Audit Account Managment policy already monitoring sucessful changes to membership of all groups, by default? Shouldn't they rather have just said that the Account Management policy does that by default, but to see the previous and current value you need to enable Directory Service Changes policy.
That wording just got me confused on the difference between Account Managment and Directory Service Access policies.
(I understand that the Directory Service Changes policy, which is being talked about on that page, enabled with Auditpol lets you see previous and current values, so thats not in question here.)
"As an example, if you want to monitor changes to the membership of a security-sensitive group such as Domain Admins, you can enable the Audit Directory Service Access policy to audit Success events."
But isn't the Audit Account Managment policy already monitoring sucessful changes to membership of all groups, by default? Shouldn't they rather have just said that the Account Management policy does that by default, but to see the previous and current value you need to enable Directory Service Changes policy.
That wording just got me confused on the difference between Account Managment and Directory Service Access policies.
(I understand that the Directory Service Changes policy, which is being talked about on that page, enabled with Auditpol lets you see previous and current values, so thats not in question here.)
Current certs: MCP (210) MCSA (270, 290, 291 and 680) MCTS (680, 640)
Comments
Now I understand that Directory Service Access policy can audit far more changes than the Account Managment one, because it also audits changes in properties and such, but still in the case of group membership changes, Account Management policy clearly spill the beans.