Showing broadcast and multicast on the same graph results difficult to see if there are packets of different sizes. The larger amount distorts, makes the smaller one invisible.
A typical case is looking for a broadcast storm, about 128-1024 packets per second, but we can’t find it because a normal 30k packet per second multicast passes through the same port.
It is quite excellent to create an alert rule for the incoming broadcast storm, as there is an element to select for it (port_statistics.ifInBroadcastPkts_rate), but this cannot be seen in a separate graph, which would be important to see and analyze the problem in time.