As Theo provides it is all about balance. Both in the BG and LMB populations. To achieve your goals you manipulate/manage both , to get the desired results. The down side to your exact question is if you remove no BG and the LMB population can not eat enough to control them they will overpopulate and may cause a stunted BG population (many 2-4 in.BG). This can be as serious as a stunted LMB population and can actually cause such a result. It can also cause poor LMB recruitment as the hoard of 3in. BG eat all the LMB eggs and fry.