First of all, congrats for the beautiful setup and wilds. Thanks for sharing the video. To avoid reflection and get better images, film or photograph at nigth and switch off all the lights, with the exception of the tank's lights.
A few weeks ago one of my cuipeuas became a big bully in my 80g, but no other fish would dare to face her the way your video shows (I think it is a lady because she started to clean the intake of my filter - no eggs though). In my case, the tank became much peaceful a few weeks later, especially after I added two more cuipeuas (I now have 7). So I also think they will figure out things themselves.