I am shooting for a trophy bluegill pond here so bass crowded is good for me. but with that being said, i feed my bluegill good food and a lot of it and i think i may be able to have a good bass fishery as well. i have a 10 or so bass that are pellet trained that are in a class of their own. i do try to catch and cull lots of bass though. i can't imagine trying to stay ahead of the bass in a 20 acre pond. you guys are going to have to be really dedicated fisherman. I would suggest installing a feeder, even if it is just one. i have a friend with a 30 plus acre pond (old quarry) and he is having good luck gathering fish to one feeder. i am going to attach a link to a picture of what i call my shark cage. the fish in the cage were never added. i hung it off the side of the dock and tossed feed in it daily. the fish just hung out until they were too large to get out. there is a bunch of fish in my cage. i think you could do the same thing and release bg from time to time.
https://photos.app.goo.gl/fcy7sy5feZLaXmFRA

Scott Hanners