I frequently have 2 or more prs of clowns in tanks I take care of. The ocellaris complex seems the most accepting of other clowns, followed by the skunk complex. In a 5ft 90g I have a mixed pr of ocellaris and black ocellaris laying eggs every couple of weeks and they allow a juvenile black ocellaris in their colony. In the same tank there is a spawning pr of pink skunks.
In another tank 54g, I have a spawning pr of perculas with a pr of black ocellaris.
And in a 72g a pr of pink skunks shares a section of the tank with multiple bubbletip anemones with a pr of ocellaris.
What has helped to allow these instances to work is having plenty of places for each pr to have their own host, starting with individuals as small as possible, sticking with the smaller more peaceful species, and adding them around the same time.