ive seen tanks full of triggers together lots of times. people on here do it. it can work. make sure to get an odd number so theres not just one dominant and one submissive one and get species that will grow to be the same size and start them off at the same size. a bare tank will leave lots of open space to fight so have lots of rocks and crevices where triggers like to perch for the night. if they cant see eachother theyre not gonna fight, think of it that way. nigers and picassos are more docile while clowns, queens, and titans are the meanest. just pick ones from the same temperemet and im sure it would be ok to have three or so.