(just using 'En' prefix as a demo naming convention)
Enfire1,2,3 being melee range spells (sword) (they make a combo),
and EnLightning1,2,3 being instant cast caster spells (they make a combo, too. EnLightning spells deliver higher potency when outside melee range <like MCH/BRD DPS in PVP>).
But then throw in low-recast OGCD gap-maker & gap-closer abilities with better DPS and/or Debuff combos like Enfire1 > Enfire 2 > (gap-maker) EnLightning 3, or EnLightning 1 > EnLightning 2 > (gap-closer) EnFire 3.
The healing side of RDM kit could just be party Support CDs, like how we've got Mantra, Divine Veil, and others.