Ye Olde Fish Truck strikes again. Been there, done that - now have dozens of master angler bullhead in my dream fishery thanks to infected FHM truck order. Impetuous, budding fishery manager I was - in such a hurry - made many mistakes. Sigh.
If one HAS to opt for truck stocking - for the love of everything sacred and holy - please hand sort and be very familiar with the discernable traits of the species you need to stock. RES or BG in 1-2" range are IMO too small to easily ID and mistakes seem inevitable.
Jwann don't you have a few public waters near you with RES? Go RES fishing [1/32 oz jig and crawler on/near bottom] and stock adults. Be sure to check for any signs of disease - think about a salt water bath first, too. They'll pull a spawn next year and your snail management issues will be addressed.
If you stocked NBG, they are now a permanent species in your fishery. I made the same mistake - with cool water species predators [HSB, SMB, YP, WE] and my nets/traps/angling the only BG population management tools available. As advised by others, my fishery is proof that heavy populations of apex predators will still allow you a HSB/SMB/YP/WE fishery with BG present if you really want one. You need to employ ladder stocking and I recommend supplemental pellet program too. Keep dense shallow structure to a minimum or remove as much as you can if you already placed it. If you can remove some vegetation annually that also helps. These management techniques all help manage BG populations, and once your HSB hit the 24"+ range and SMB 17"+ they can start hammering 4"+ BG and this helps a ton, too.