Started with only 3* and 4*s, finally got my first 5* in my 4th roll yesterday, and now I'm doing pretty well on leaderboards. Hoping to win another defense which should push me up pretty high.
My main party right now:
http://imgur.com/a/t7nB3 + reserves
I started with 3* Cherche, 4* Cecilia, 4* Catria. Added in 4* Caeda from my second roll, and 4* Lilina in reserve. Added 2 x 5* Takumi on my 4th roll. Takumi replaced Cherche, giving me a stronger balance of ranged and hand to hand combat. I upgraded Cherche to 4*, but after I leveled Takumi he's just way better overall. Caeda is pretty strong in the right situation, but her base attack is slightly disappointing.
Should I train Lilina a bit and replace Caeda with Lilina (I'll have one of each colour and 1 clear)? I could also swap Cecilia for Cherche in the interest of having 2 ranged and 2 hand to hand. Cherche was a monster offensively through main story even as a 3*, so I imagine 4* Cherche is even better, but Cecilia has the advantage that she absolutely destroys armoured knights with her magics. I feel like green magic is stronger against armour compared to fire, but I'll have to test. Can't remember if this was true in the main games.... Cherche with Hammer is pretty good against Knights too, but then the weapons triangle comes into the mix. With Cecilia I didn't have to worry about that.