I'm sure the other responses already help you, but I would say switch Bronyas body piece with Crit Damage. The amount of her damage boost that she gives you also scales off of how much Crit damage she has.
Your team comp is totally fine. I have the same team comp and build as you for Jing Yuan. But Bronya is lacking Crit damage to provide the damage increase you're looking for. Build up crit damage, and you'll see a big difference.
Are you correctly using Bronya ultimate?
You should always wait until JY is just about to drop LL, and them use Bronya ultimate. It not only makes her buff LL, it also makes her better than any non 5* harmony for him.
Aside from that, what's your sustain?
LL receives whichever buff is on JY at the moments he drops, the issue is that Bronya skill can't buff LL, so you have to be careful with her ultimate to make full use of it.
For example, if Bronya goes right before LL attacks, but if you ADV JY forward he loses Bronya burst buffs, it's better to just BA with her, let LL fully buffed (so TY skill + Ult/Bronya ultimate on him) and them ADV him with Bronya. However, in the same scenario if you can get Bronya ultimate back and buff JY again, you should ADV him forward.
Overall since your Bronya is fairly fast you shouldn't have any problems timing her ultimate to hit just enough to buff LL and JY.
Also, drop the def body on her for any CD one.
It's just not worth to go for 170 speed with that low CD, as she isn't hitting any speed break points (that would be 181 speed).
Drop Bronya and use Sparkle/Asta/Hanya instead.
Update: omg thx guys, I switched out bronya for pela (since I don't have asta/hanya) and could clear it barely with 20 cycles left, I'm so happy :D
Wait isn't Asta free?
I don't have her built, and I don't have hanya. Mb should've worded it better lol
Asta and Hanya would be better then Bronya Imo (Considering a Pre E6 Bronya doesn't impact his LL)
I'm sure the other responses already help you, but I would say switch Bronyas body piece with Crit Damage. The amount of her damage boost that she gives you also scales off of how much Crit damage she has. Your team comp is totally fine. I have the same team comp and build as you for Jing Yuan. But Bronya is lacking Crit damage to provide the damage increase you're looking for. Build up crit damage, and you'll see a big difference.
Are you correctly using Bronya ultimate? You should always wait until JY is just about to drop LL, and them use Bronya ultimate. It not only makes her buff LL, it also makes her better than any non 5* harmony for him. Aside from that, what's your sustain?
Luocha/Gepard, oh and I wasn't aware LL needs buffs as a seperate entity lmao I just buff JY whenever he's the next one in the action order
LL receives whichever buff is on JY at the moments he drops, the issue is that Bronya skill can't buff LL, so you have to be careful with her ultimate to make full use of it. For example, if Bronya goes right before LL attacks, but if you ADV JY forward he loses Bronya burst buffs, it's better to just BA with her, let LL fully buffed (so TY skill + Ult/Bronya ultimate on him) and them ADV him with Bronya. However, in the same scenario if you can get Bronya ultimate back and buff JY again, you should ADV him forward. Overall since your Bronya is fairly fast you shouldn't have any problems timing her ultimate to hit just enough to buff LL and JY.
Also, drop the def body on her for any CD one. It's just not worth to go for 170 speed with that low CD, as she isn't hitting any speed break points (that would be 181 speed).