Can't stock TP in open systems in MO.
My first suggestion is to get a consult with a real pond pro and put a shock boat in there to see what you're dealing with.
Short of that, get a relative weight chart, a ruler, and a scale, go fishing, and document three sessions. I think you'll find that you have numerous small, thin bass and rare, relatively large bluegill. I'm guessing here but also probably numerous 4" crappie.
I don't really know how to manage the species that you have. But a harvesting plan can work -- click the link in the signature to see the results of selective harvesting LMB at our place.
