That might work ive seen the large pet spieces packed tight but there will be loses from canabalism, mismolts, etc. A 5 gal is a good short term solution just plan to give them more space as they start to reproduce. These are very different then feeder spieces that thrive on being close together. I know in crickets when thier antenna touch it causes a stress responce if its to frequent. Some roaches are very similar haveing "battles" just by hiting thier opponents antenna with thier own. Hissers are well known for these terratorial disputes. In general tree and cave dwelling roaches are more teratorial then leave litter/ground dwelling roaches. Hopefully others will chime in to confirm this cause I dont want to come across as a negative nancy lol I just want you to have the best possible expierence raiseing this fun speices.