The RACI matrix shows you who is responsible, who is accountable, who is to be consulted, and who is to be informed related to particular work packages.
The roles and responsibilities listed in the subsidiary plans are more broad in one sense because they don't pertain to specific work packages, but on the another hand they go into detail about roles that may not necessarily to relate to work packages. For example, this could be the roles and responsibilities for the Scope Plan:
Sponsor:
Approve or deny scope change requests as appropriate
Evaluate need for scope change requests
Accept project deliverables
Project Manager:
Measure and verify project scope
Facilitate scope change requests
Facilitate impact assessments of scope change requests
Organize and facilitate scheduled change control meetings
Communicate outcomes of scope change requests[/li]
Update project documents upon approval of all scope changes
Team Lead:
Measure and verify project scope
Validate scope change requests
Participate in impact assessments of scope change requests
Communicate outcomes of scope change requests to team
Facilitate team level change review process
Team Member:
Participate in defining change resolutions
Evaluate the need for scope changes and communicate them to the project manager as necessary
And here could be the roles and responsibilities listed in the Procurement Plan:
Project Manager:
Approve Purchase Order
Procurement Manager:
Confirm Delivery Timeframes
Resolve Delivery Issues
So the RACI isn't an integrated tool that is a collection of all the roles and responsibilities, it merely describes a particular area of roles and responsibilities, and that roles pertaining to specific work packages.