Some things that make Agile work are teamwork, multidisciplinary collaboration across functions and an uninterrupted flow of work cutting across functional silos. This enables continuous delivery of value to the customers, fast feedback loops, and fast learning. In such a setting, business units, or product/service units replace the functional silos and the product/service team's backlog replaces the function's backlog. Paradoxically forming an Agile Transformation Team or a team of Agile Coaches means adding one more functional silo, where team members pull the work from the functional silo backlog and not the backlog of the teams they are supporting as they should. Things sometimes get even worse when inside such a team there is a hierarchical order for example between "Enterprise" Coaches, Agile Coaches and Scrum Masters.
Agile as another functional silo.
Instead, change agents such as Transformation Leads and Agile Coaches should belong to and be embedded in the teams and departments they support and pull their work from the backlog of those teams. They should be connected among themselves via a network and act in a federated way similar to the way Communities Of Practice work, where the leadership of the CoP is shared and distributed among the members.