The Diamond goby doesn't just eat pods, it's eating all different types of micro-fauna in the sand. You can do it if you dont have a small tank(40 or bigger would be "easier" 100 gallon+ would be easiest). I have a dragonet pair and a large Diamond goby in my 120 along with a Dusky wrasse and Ornate Leopard wrasse, all pod eaters. The Diamond goby and the male scooter will "fight" sometimes, but more for territory then food IMO and they can't really hurt each other, the Diamond goby generally uses it big mouth to just move the scooter blenny. I have a bigger issue with my male scooter always trying to fight my lawnmower blenny.