I assisted a friend of my father's establish a few ponds on his property for "prepper" type purposes. I too agree with the LMB, BG, RES recommendations. Most original stocking numbers and species recommendations were for food and not fishing purposes.
The classic 500 BG to 100 LMB per acre numbers was from the 30's and the Great Depression when people were looking for food. It's a tried and true recommendation. Adding the RES to this is additional insurance.
For your purposes I'd stock 450 BG and 50 RES this spring. This fall I'd stock 50 LMB. Harvest mostly BG allowing the LMB to remain plentiful in the 10" to 12" range. This will lead to numerous food size BG and RES in the 6-9" range and numerous LMB in the 8" to 12" range for harvest for food.
My dad's friend also has a pond he raises common carp in. They actually produce the most pounds per acre of fish protein. He has multiple ponds to work with, if you add a second pond, I'd look at common carp as an option. The sheer pounds per acre that can be produced by common carp is nearly unbeatable.
Look at having a large seine kept on site for fish harvest. Fishing by hook and line is too inefficient and time consuming in emergency prepping situations. I'd also consider some gill nets which are often illegal but highly effective if SHTF.
