Aaron, depending on what you want, it sounds like you have a good mix to support multiple predators. The Shiners will help you in trimming down the Crappie, GS have the reputation of raiding nests during the spawn, just like Crappie have the reputation of raiding the young of year because they hatch first. If you like Crappie, by all means keep the adult shiners in there to support the balance. The GS will raid all nests so there is a price to pay considering your Bass population. I welcome GS to my pond, they were well established with the bgill before CC, LMB, HSB, Tilapia, and Crappie went into my pond this Spring. So far everything looks good..I expect everything to complicate itself in the near future. If Tilapia are legal in your area, I highly suggest getting an aquarium and starting a few up, they are miracle workers for forage and clean up a lot of mess.