At 12-13", Max ignores feeder fish pretty well. I had thought that he was playing nice until he recently ate my 6" FATF and killed a tarpon and tinfoil barb. I'm pretty bummed out about all that.
Once I get my 510 up and running, I was actually planning on trying some smaller Africans in it as dithers, knowing full well that either Max, Dottie or Drogo is quite likely to pick them off over time. I was tempted to go with a proper African biotope, but I love my aro and goonch too much to do that. Oh well.