Lulu can handle the orb, while Garnet and Ramza does so much damage that the Sweepers die before they get a turn.
The only risky situation is the final sweeper at 19%. By that time your BT auras would have expired and you may have trouble killing the final sweeper. You cannot let the final sweeper act otherwise it will give the boss a turn with full mBRV and you will wipe.
In theory a 100% Auto+ is possible if Lulu and Ramza can both pop EX on the final sweeper, but that is too RNG reliant and not consistent. So I went with Auto+ with the exception of popping summon mode.
Timestamp
Party setup at 6:36.
Unequip Garnet EX and Ramza's Galvanize skills.
Garnet had 5/5 UW, Ramza had 0/5, and Lulu had 2/5 UW
0:00 Commentary start
1:56 Commentary end
5:18 Popping summon