The crew could be RG or Storm, and obviously Palpatine.
Storm is mostly there because they are the Empire basic force, though I wouldn't expect him to be in there since the Emperor is normally with few Royal Guards.
Royal Guard is probably the best option there, though it's hard to see him in this shuttle since his kit need kind of a full rework.
To that extend, devs, if you read me, I would love a rework of that kind :
Force Pique - Deal physical damage to target enemy with 50% chance (double if shocked) to inflict speed down for 2 turns. If RG as more than 50% health, this attack stuns the target for one turn (it means it goes to 100% chance instead of 80%).
Imperial Phalanx (3 turns CD) - All allies gains defense up and health up for 2 turns. Royal Guard gains 35% turn meter and 5% more for each Empire allies.
T-21 shot (3 turns CD) - Deal physical damage to single target enemy and recover protection equals to 100% of the damage dealt. If the target was debuff, cleanse all debuff on a random ally and grant him retribution. If the target was shocked, Royal Guard also gains these buffs.
Unyielding Defender (Unique) - If Emperor Palpatine is present, RG gains taunt at the start of the battle and whenever the Emperor is inflicted a debuff. When an Empire ally falls bellow 80% health, RG equalize his health and protection on all allies. Whenever an ally his target, RG gains 15% turn meter and 10% health.