Slow down and don't add anything until we go through this situation.

What exactly did you see and the state biologist say ?

What do you want the place to be ?

I saw no mention of BG , RES , GSF etc nor GShiners , TShad. Are you set to grow BG in the small pond ? GShad can be a real problem in limiting (taking up and suppressing) fish reproduction and carrying capacity. Crappie can also do this and stunt as well. Crappie generally have a population cycle that makes them hard to manage in a pond. You have more room but the habitat is monolithic from the pic. but fertile. Just because all the crappie are X inches does not mean they are stunted. That could be the stage they have reached in the population cycle. You have a lot going on in the pond and it would help to write all you see/know down so others can look and advise. You have options but stocking more fish without knowing the status could be a waste of $ . Did you tell the state guy all you know/have seen including about the BG project? Is he doing a report ? Try doing a timeline of pond events like original pond status ,then fish added , average harvest ( type ,size and #) and general pond info like size , depth , fertility etc. Do you intend to feed?