If you look at their Accor matches only, their average was just under 24K (23,765). Take out the Roosters game (which was heavily rain effected) and that jumps up to almost 26K (25,839). Whilst I feel 30K is difficult, it's not completely impossible from where they finished.
v Roosters - 7,169 (Rnd 5)
v Knights - 17,784 (Rnd 7)
v Wests Tigers - 17,068 (Rnd 9)
v Dragons - 15,442 (Rnd 12)
v Eels - 45,496 (Rnd 14)
v Sharks - 15,765 (Rnd 17)
v Warriors - 27,223 (Rnd 18)
v Sea Eagles - 35,502 (Rnd 26)
v Cowboys - 32,437 (Rnd 27)