They could... If by "If" you're asking IF it's possible. Sure it is. But not likely that anything will survive a group of Brichardi in a tank less than 6-8 feet. you'll start finding finless floating transcriptus at some point I'd wager but the cyps will probably just kill themselves via leaping or just slimming from the stress of being harassed. The shellies will die sooner.
All that being said Brichardi are cool and worth keeping in a species setup.
Given all my fish are young, I have N. helianthus with 4-week old fry in a 29g with some transcriptus and T. vittatus juvies. The tank is profused with Java Fern that probably shrinks down these "Brichardi Complex" fishes territorial needs. I also do something different which most people probably won't like-I use Swordtails as dither fish (4/tank). I"ve been doing this for over a year and it has really cut down my losses among my precious cichlids. I use them because they use the upper tank and handle the pH and hardness well. Other than their use I really want my tanks to look as L. Tanganyika as possible and build intricate rockwork structures assembling them with tank seallant.
You almost forget to see the dithers and the Java Moss you can imagine to be algal growth if kept trimmed.
I have been patiently waiting for the "un-Civil War" to break out in any of my 4 similarly stocked tanks but so far it hasn't. And yes, I am planning a N. helianthus only tank and have a 40g (160 l.) almost ready to start cycling-in.