Why do the signer dragons have other archetypes they belong to?

The signer dragons other than Stardust Dragon & Ancient Fairy Dragon belong to different archetypes. Red Dragon Archfiend: archfiends, Black Rose Dragon: Rose, & Black-Winged Dragon: blackwings. What's the purpose of creating an archetype that that doesn't support each other while the majority supports others. Nothing that doesn't support my question or I'll report. But Please but put down your answers if it does.