How do I build a team with Vildred, Sez and Destina?

Didn't know that lower star units were part of actual team compositions as most previous played mobile games tend to focus more on higher star based unit compositions. Been using Ras - Vildred(Daydream Joker, Speed, Crit) - Sez(Exorcist's Tonfa, Attack) - Destina(Celestine, Health, Health, Def).

I have Romann, Pearlhorizon, Carmainerose, Rima, Elson, Jena, Carrot, Mucacha, Enott, Roozid, Alex, Kluri, Aither, Merc.