If bass are removed in numbers significant enough to improve their average size, the only way the average size of the bluegill will not suffer is if large numbers of bluegill are harvested - for a lake that size, several hundred pounds of bluegill would have to be removed each year, especially considering it's in a northern state where bluegill have been shown to be much more prone to overpopulation in the first place. Bluegill never, ever are not going to be prolific; if the numbers of predators are significantly reduced and counterbalancing measures, i.e. aggressive, sustained harvest or the addition of another predator, are not employed, the bluegill are going to overpopulate. That's pretty incontrovertible.
But if bluegill are harvested (a bunch, every year), I agree that a balanced lake could be maintained. Although even then, the angler or anglers doing the harvest would have to agree to harvest only intermediate and smaller bluegill or else the size structure would still be negatively impacted: if only the larger bluegill were harvested each year, it could easily and would most likely lead to genetic deterioration due to cuckolding, a phenomenon that has been discussed more at length in PB magazine and other places. The state of Illinois has also recently done studies on the importance of protecting the larger bluegill in a population for maintaining a good average size. Muskie or pike, short of fish of state-record size, are not going to eat as many 9"+ bluegill as they will smaller specimens because of the body shape of the bigger specimens and the difficulty of swallowing them; but fishermen would much rather keep a large bluegill than a small one. But, assuming very cooperative and conscientious fishermen in the HOA who are willing to take the time to catch and remove thousands of smaller bluegill each year, harvesting could work.
