Pond Boss Forums STOCKING A NEW POND Types of fish to choose What to stock in my pond?

I would add the 5-6" BG, also consider some HBG as well. They tend to be more aggressive toward the feed and could help train the other BG.
Tough to say on how many to stock, a lot of variables. By removing some LMB you are adding by subtraction as more BG will survive as you remove the LMB. I would take some length and weight measurements on the LMB and remove as needed based on the relative weight charts.

+1 on adding HSB, they are my favorite fish...fun to catch and to watch feed. They grow fast and fight harder than any other fish.

FHM would be a waste of $ in your current pond situation.

Sounds like the guy who built the pond doesn't fish much, any chance for you to buy the property and have full control of the pond? This way you protect your investment in the pond and if something happens to your neighbor you don't have any surprises in terms of what the new owner wants in the pond.