I keep many of my tinctorius in groups, and generally do not have issues. Occasionally, it does not work out, but most of my tincs that were raised up together seem to do just fine. My average tank size is 24x18x24 inches, and they are fairly heavily planted, with many visual barriers incorporated into the design so that the frogs are not staring at each other all the time. Groups that are currently working for me in this size tank are: 2.3 yellowbacks, 1.3 powder blues, 3.2 boulanger, 2.2 brazilian yellow heads, (probable) 2.2 green sips, (probable) 2.2 lorenzo. All of these tincs are at least a year old, and several groups have been housed together for multiple years.