I suggest feeding more veggies for two reasons, firstly it's good for their GI tract to keep the plant matter running through it. and secondly the time taken to rasp at the veggies will lessen the agro as they will be too busy eating. Be sure to feed enough pieces for all the plecs and feed in different areas so each one can eat in peace. Just my .02$ but I have had very overstocked tanks from time to time and feeding seems to be the key to happiness.
