You can call it a universe switch, but keep in mind that they aren't the same characters at all though Archie used the names from Sonic Underground. Archie: Sonia = ground squirrel (around 15-16) similar to Sally in design; Manik (with a "k" not a "c") = blue hedgeghog (around 10-11) similar to Sonic in design. Sonic Underground: Sonia = pink hedegehog (15/16); Manic = green hedgehog (15/16) where both are different from Sonic in design. --True Red
About Manic and Sonia: Is it only in the "Archie Universe" that they are Sonic and Sally's children? Because, in the Sonic Underground series they're siblings. Is it just a universe switch that makes them siblings in one, and father, mother/children in another?