I’ve noticed that a few older heroes fit thematically with Atlantis families. For example Obakan and Sumitomo have nearly the same SS. In fact I think someone recycled Obakan’s SS animation for Sumitomo.
Cabin Boy Peters seems to have come straight out of Concordia based on how the wildlife has the same Silencing power.
The family power bonus isn’t all that much of an asset, but it would be a cute nod and callback for older heroes to retroactively add the family trait to such heroes.