I would not be concerned (yet) about too many BG as long as a fair number of those 90 LMB are still in your pond. It is always hard to guestimate how many of the original stockers survived. If your water is anything near clear, you should be seeing bass all over the place.
In my pond, I had a good sized LMB spawn last year when they were 10-11 inches. No BG were present at that time. If you find that your bass have spawned, you may want to consider removing some LMB this year. 90 11" bass will go through a lot of forage. I think you may start seeing the smaller intermediate BG decreasing and your original bass should put on some weight. At this point I would begin thinning lmb unless you are going for a bass crowded environment (slow or no LMB growth). In the average .6 acre pond, most of these 90 bass will need to be removed if you want to sustain reasonable growth rates. You might as well get started.
