Recently hit level 70 with Bard and it's my first DPS job at end game so I decided to practice my opener/rotation and ended up (barely) clearing the O2S dummy. However I was watching some videos of Bards with a similar item level who are able to output around 3800-4000 DPS. The most I could get after several tries was 3660 and more often than that it was around 3400 or 3500.

https://www.youtube.com/watch?v=NUHARv7hOKo

I've made a video showing the clear and I was wondering if anyone has any tips for me to squeeze out that extra few hundred DPS. Are these higher numbers just a result of a crazy good RNG set or am I doing something wrong? I really appreciate any advice anyone could give me. (Note that the video is not edited, it's just missing a few seconds near the 28-second mark because my Twitch stream decided to restart itself at that moment for no reason)

Thanks in advance.