Welcome to the world of Eurobeat (well, dance music in general).
You will see this across many different genres (House, Trance, Psytrance, Happy Hardcore, Techno, etc). It gives labels a "wider catalog" of sounds/avenues. Look at ALL the tracks Clara Maroni has sung. It would look bland for a record label to have Clara Maroni listed over 100 times.
And also, picking a new alias provides a singer/producer to try something different. For example, take Daft Punk: for 3 albums, they pumped out french disco/techno sounds...then Random Access Memories came out, and sounded NOTHING like Daft Punk(as we knew them).
So, with Eurobeat, you find it easier to associate artist names with certain labels. Like, Go Go Girls would be A-BeatC/GoGo's Music...Cherry would be Delta, Franz Tornado would by Hi-NRG Attack, Irene is SCP....Once you learn the ring of the labels, it will be better.
Here's another example from one of my favorite Happy Hardcore artists:
Scott Brown
Aliases: Annihilator, DJ Equazion, Dream Collective, Firestarter (2), Futuretribe, Genaside, Genetik, Hardcore Authority, Hardware (3), Lord Of Hardcore, Mook (2), Mr. Brown, New Style Anarchists, Orbit (2), Plus System, Punisher (2), Scotchman, The, SP 12, Trance Fiction, X-Tech (2)
In Groups:
Analogue, Bass Reaction, Bass X, Dansatak, De-viation Crew, DJ Neophyte & Scott Brown, Equazion, Hyperact, Interstate (3), Kinetic Pleasure, Marc Smith vs. Scott Brown, Massive, Q-Tex, Queens Boro Crew, Renegade & Static, Scott Brown & Brisk, Scott Brown & Gillian Tennant, Sub Source
....so it's not just Eurobeat