Sorry about the pixels and frames, but I really wanted to show this. Shout out to them Stings though.
E0S1 Rappa, E0S1 Dahlia, E0 Fugue and E1 Ruan Mei.
I got S because of the unfortunate Pollux with Boss Enhancement and Permanent Trauma affixes, which killed like 30-40 hp because my DOT early team couldn't sustain Pollux at all. This also won plane 3 Encounter difficulty 4 easily. The emblem is important to remove one slot from the team, which make the team effectively functional at level 8. 4 GR (Boothill) isn't necessary as I got the wealth gem from the plane 3 Encounter.
DISCLAIMER: This is just a for-fun kind of team, so if you want to try this, proceed with caution. The on-field line up is RMC, Sunday, Tribbie and Welt (E2 but not too important), with Eagle set on everyone except RMC and 2 S5 DDD. Also sorry about the pixels.