ok 17 chars, 3 teams. so we have to drop 2 chars.
2 worst empires are magma and imperial super commando and Gar
we have
vader palpy ipd gar/magma rg tfp storm snow shore death tarkin krennic veers starck and. Thrawn.
Thrawn is top tier Empire leader
Palpy, Veers Krennic are next best
Tarkin Vader lead is mediocre
Gar lead is pve viable at best
So
1. Thrawn/ DK, DT, Shore, Storm. This team for defense& against CLS JTR
2. Veers/ Starck, Snow, Gar/magma, RG. The first three have to go together. Trooper team against NS
3. Palpatine/ IPD, Tarkin, Vader, TFP. This team is against no counterattack teams. For offense mainly.
4. Gar/ IPD, ISC, Tarkin, TFP if you want to use two Sith in other lineup. Good against AOE teams