1. A method, comprising: receiving, at a particular node in a computer network, an indication of a number of child nodes of one or more potential parent nodes to the particular node in a multicast and broadcast (MaB) directed acyclic graph (DAG); selecting a particular potential parent node with a highest number of child nodes from a plurality of nodes with children as a DAG parent for the particular node in the DAG; joining the DAG by the particular node at the selected DAG parent; determining a particular number of child nodes that have joined the DAG at the particular node as their parent; and advertising the particular number of child nodes into the network for the particular node; and adjusting the particular number of child nodes that is advertised with a phantom number of child nodes.