Stuck on Hulao gate in origins

I've done this mission over countless times now and i don't understand what i'm doing wrong. Im rank 23 with 80-90dmg weapons, playing on wayfarer. In the last part where you storm the base, it just seems to take forever to actually progress through the objectives and take out the officers to get the large force meter down. I have all bases ready to charge so I can't get anymore allies. I usually just end up rushing to take on Dong Zhuo because i'm running out of time since Lu Bu is killing Yuan Shao. ISurprisingly I haven't seen any posts talking about how insanely difficult this mission seems to be, so I must be doing something wrong.

Any help would be appreciated. Having to do this over an over is fucking maddening.