Welcome to the forum MSsawyer!!

I would do a lot of fishing using live bait and several hook sizes to see if any bass are there before trying to add anything.

Do you have a lot of plant life for grass carp to eat? If you have over 20% of your pond in submerged plants, I'd start with NO more than 21 grass carp, stocking 7 each year for 3 years, and removing the 7 largest and replacing them with 12" GC every year after...Big GC don't eat much due to laziness.

I like a 10:1 ratio of BG to LMB more than your proposed 5:1 ratio. You can consider stocking Coppernose BG instead of northern BG also, both should do well there in MS. I'd consider adding Hybrid Striped Bass instead of Black Crappie.....If yuo really want BCP, consider stocking Hybrid BCP that produce poor quality offspring LMB can normally control