Do we know its harder or it just feels harder?
As many have said here, this is really a speed race. If you can out pace the death troopers you should be fine. Thrawn's opener will also set the tone of the fight. If he opens with fracture on ezra or zeb you might as well restart. If he uses his TM swap you're in for a good first couple rounds. Also use backup plan and kanaan taunt as soon as possible. DT's can rez block which has happened a few times on 2nd/3rd turn, but they always seem to open with grenade. I don't know if its better to daze the DTs or thrawn, but either should help.
I haven't yet finished the 7 star, however. Just did about 5 runs this AM with diff comps to test waters and read AI tendencies. Conclusion: Speed is definitely the biggest issue (and rng of opener) and will require mod swaps to get hera and zeb faster for me.
Team: Hera (L) g8/S149, kanaan g8/S113, chopper g9/S165, zeb g8/S126, ezra g10/S170