If I had to guess here's my guess (this assumes they want to make something comparable to jkl but still reasonably make sense for req.
1. Malak (palp is all the sith so any sith is fair game and malak requires the most higher gear characters)
2. Traya (once again all the sith and jml requires a raid character)
3. Thrawn (legendary and empire so probably needed)
4. Red Sith trooper (I just don't see him not being needed)
5. IPD (to even out the tb req that are needed for jkl. At least to the extent possible.)
Other likely candidates
1. Tarkin
2. GAS (but I think malak is more likely)
3. TFP
4. Stormtrooper
Replies
If I had to guess here's my guess (this assumes they want to make something comparable to jkl but still reasonably make sense for req.
1. Malak (palp is all the sith so any sith is fair game and malak requires the most higher gear characters)
2. Traya (once again all the sith and jml requires a raid character)
3. Thrawn (legendary and empire so probably needed)
4. Red Sith trooper (I just don't see him not being needed)
5. IPD (to even out the tb req that are needed for jkl. At least to the extent possible.)
Other likely candidates
1. Tarkin
2. GAS (but I think malak is more likely)
3. TFP
4. Stormtrooper
They're a great counter team against Padme squads