Young Central American cichlids can be skittish but generally mature adults like the op's aren't, in fact you would normally expect them to be flairing up and glass banging at that size but that won't happen in a overstocked tank as the fish have no territory to defend.
There are a few keepers on this site who have fantastic ca communitys, ragin cajin, sbgbuddy for example I am highly jealous of both there tanks, both of them will tell you they have to change round stock occasionally due to various reasons and the tanks can be ever evolving. If you look at the op's youtube page his stock changes all the time, there's not anything necessarily wrong with that if he has other tanks and rotates his stock about. To me he came across as basically saying you can have any random collection of cichlids and make it work if you have experience, which is miss leading to new keepers who might read this post.