I have a similar pond here in Missouri. Only my HBG mess was self inflicted. Unfortunately the HBG I stocked, have reproduced, or crossed with the RES. I keep traps set all the time for raccoons and possums to help our turkeys. I find the HBG are great for baiting the traps. As an added aggravation, they continue to nip at swimmers.
I did add golden shiners when I stocked the SMB. My golden shiners have continued to hang in there. The FHM disappeared very quickly. The SMB and YP made short work of them. The pond was actually loaded with them, as I stocked them alone a full year before I stocked anything else. My SMB have done well. Reproduced to a limited degree, but they cannot control the HBG/RES cross offspring. We have added YP a few times, as we enjoy eating them as much as we like catching them. I don’t think I would start over. Just catch and destroy all the BG that you can. If you haven’t added golden shiners, you might want to consider them.
Biggest SMB we’ve caught so far. My lovely wife has the pond record. [Linked Image from hosting.photobucket.com]

12 yr old pond, 1 ac, 15' deep.
RES, YP, GS, FHM (no longer), HBG (decreasing), SMB, and HSB (only two have been seen in 5 yrs)
I think that's about all I should put in my little pond.
Otter attack in 2023.