He is pretty awesome anywhere, works best when he is critting because with his special he gains 100% turn meter and goes again. Plus he is very fast and hits decently hard.
Once we get to lvl 80 and ability 8 his passive goes to 1/2 turn meter gain anytime any opponent dies. So if my rebel team can be arena relevant with the new update coming he's basically going to Have tons of turns.
AA leader
HRS
Han
GS
Biggs/Luke/tank/not sure/
I think in the notes they finally fixed AA where his special dispels and heals the healing immunity debuff. Still have to test it today in GW to see. Not really relevant for arena anymore since no one uses Sid.
All in all I think HRS can be used in tons of teams though since he's fast and hits hard enough.