The Path Manager(PM) is the wallet responsible for the creation of a revenue path. In a mutable revenue path, the PM can also add, update revenue paths. In a non-mutable path the PM is irrelevant after deployment of the path.
In a mutable revenue path if you cannot trust a single path manager then you either:
should not set a mutable path (you can simply abandon the existing path & create a new path if edits need to be made), or
you can set the path manager as a multi-sig, using a tool like gnosis safe, which enables group management of the path manager's administrative functions.