If you already have a modified popgroups file, do not move it (it will replace it) and manually add it to your custom file as follows:

add this to <Name>Strawberry_SC</Name> and <Name>Chamberlain_SC</Name>:

  <Item>
    <Name>g_f_y_families_01</Name>
    <Variations type="NULL"/>
  </Item>

this to <Name>Davis_SC</Name>:
  <Item>
    <Name>g_f_y_ballas_01</Name>
    <Variations type="NULL"/>
  </Item>