Thrawn definitely belongs in Epic games. I would hate to see him used as a "discard" card, but it would fit with others that have been shown to us.
"Misdirection. Swap any two ships of equal base size that have not fired a weapon. Discard this crew card."
I cannot think of something Palpatine like that would give the tactical finesse Thrawn was known for. Ship movement would definitely be where he should excel. Tactically if at all possible. An alternative that might keep him in the game would be provide a free PTL effect to any ship on the board once per turn.