You could do what you suggested with 100 adult CNBG if they were about 50/50 male /female, from 3 different genetic sources and you have enough time. 2 full years IMO. Year one 50 pairs produce between 500,000 and 1,000,000 offspring with reduced predation. If only 10% survive to adulthood then the next spawn by those and the original stockers will be in the millions range. That will fill the pond for any LMB to follow the next year.

FWIW average time to reach carrying capacity with BG/LMB type ponds in the south is 18 months.