I play Hard mode. Managed to get red crate during Malgus time and this time I just finish all battles without feats. And most of the time I use 3,5 teams: Darth Revan team (r8-9), Triumvirate (r7), Palpatine+Mara (r7-r5) and sometimes Grievous+Wat.
Half (or more) of the success is to choose right discs and use them with the right team. And change them if needed. And use stimulants and medpacks etc. if enemy is too hard.
And if the mode is too hard to move at all... Well, no one said that it should be finished by everyone ?