normally having a high rarity team like yours will assure firepower for any battle but, high rarity unit has higher cost and that will slower your deployment so a complex team with silver and above is better, or you could just roll and reduce cost of high rarity unit.
for daniella, thing happened and if you mean to replace her then keep her as fodder for later AW
edit: i am so jealous i rolled a lot and yet never got a plat unit