Removing bullhead would be a good first step. If you do this with another predator then the way the balance ends up between predator and YP is too hard to predict. Instead, you could build a cloverleaf trap or two and trap out the bullhead. Others have had success removing hundreds of bullhead this way. That would take time but could help tip the balance.
The next step is forage for the YP. It appears that FHM is the only forage for the YP. You were hoping they would eat the small BG and RES but perhaps that isn't working out. Can you source some spotfin shiners from a local body of water or from one of the several Ohio fish farms? They seem to be able to hold their own in a pond with larger predator fish compared to FHM which can disappear in a short order.
Could also consider GSH.
Also I'm not sure how much this would work for you but could you consider supplemental pellet feeding for the YP? Not sure if they are pellet trained or could learn to eat pellets off the bottom in a feeding area if you got them in the habit of it?
