"The Content Metamodel defines a formal structure for these terms to ensure consistency within the architecture description..." A metamodel used across the enterprise enables consistency and completeness checking of the architecture description against the defined structure. Open Group Publications Reference: The Open Group, TOGAF 9 Conformance Requirements-Content Framework/Metamodel description.

According to the TOGAF standard, the need for the ADM process to be governed is to ensure that the architecture development and implementation activities are conducted in a consistent, coherent, and compliant manner1. Governance provides the means to verify that the method is being applied correctly and effectively, and that the architecture deliverables and artifacts meet the quality and standards criteria1. Governance also enables the management of risks, issues, changes, and dependencies that may arise during the ADM process1.
Some of the benefits of governing the ADM process are2:
*Improved alignment of the architecture with the business strategy and objectives
*Enhanced stakeholder engagement and communication
*Increased reuse and integration of architecture assets and resources
*Reduced complexity and duplication of architecture efforts
*Increased agility and adaptability of the architecture to changing needs and requirements
*Improved compliance and auditability of the architecture outcomes and outputs References: 1: Architecture Governance 2: Architecture Governance Benefits

According to the TOGAF standard, the two statements provided refer to different scopes within which architecture can be developed:
Groups of countries, governments, or governmental organizations working together typically align with broader, often international, scopes of architecture that transcend individual enterprise boundaries.
Partnerships and alliances of businesses working together, such as a consortium or supply chain, refer to collaborative efforts that can define architecture at a scope involving multiple enterprises.
In both cases, the term "Architectures Scopes" is appropriate because it reflects the varying levels and contexts in which architectures can be defined, ranging from single business units to collaborative inter-organizational efforts.

The purpose of the Architecture Roadmap is to provide a high-level view of how the Baseline Architecture will transition to the Target Architecture over time. It lists work packages on a timeline showing progress towards the Target Architecture, as well as dependencies, risks, and benefits. The Architecture Roadmap forms part of the Implementation and Migration Plan and guides the execution of the architecture projects.
References: https://pubs.opengroup.org/architecture/togaf9-doc/arch/chap20.html