Guys, you are complaining too much - it's very feasible with all G8 and even bad mods if you know what you are doing.
https://swgoh.gg/u/dado90/collection/?f=phoenix
There, that's the squad I just used to get Thrawn down on my first (!) attempt. All G8, no Sabine, junk mods I had lying around because I didn't want to touch my arena team, too much of a hassle. Only Ezra had okay speed (like +50), followed by Hera who had like +30 speed and all 3 tanks almost no speed, only protection on all possible mods (arrow, triangle, cross, circle with primaries, secondaries all over the place) because they need to survive as many fractures as possible.
Tactics: be smart! Dispell the taunt, the two DTs get full counters after their AOEs and should have lost almost all of their protection. Dispell at least one of their buffs with Chopper. Afterwards it's super simple - you have to taunt with Chopper, he gets fractured. Then you taunt with Kanan and keep his protection up with Zeb and himself. If needed use Hera's revive. Then get Chopper's protection up again and watch the taunting Kanan get fractured. Just keep repeating this "taunt rotation" between Kanan and Chopper and replenishing their protection as much as possible. I actually didn't use Hera's revive at all. And while doing the "taunt rotation", Ezra and Hera use each other for assists - first the DTs, then the healers, then the pre-taunter and Thrawn last. I know people say that you should call Zeb for daze and stuns but nope, I went with Hera-Ezra-Hera-Ezra all the time and it paid off.
As a reference point: Thrawn fractured and killed Kanan (Zeb and Chopper were dead before him so no more tanks from this point on), with my next assist from Hera-Ezra his protection was gone and I just kept lashing out on him with the assists and specials until he was dead, he didn't get in another fracture.
They didn NOT make the event harder. G8 definitely IS enough. Play smart, maybe have a bit of luck and get your 7* Thrawn - it's absolutely possible.
If I had used my arena mods (which you can also see on swgoh.gg if interested) I possibly could have auto'd it or at least gone without losing a single toon.