Welcome Theeck!
I don't have any experience with reintroducing forage fish into an LMB environment, But I can tell you that if a smaller fish will fit in the predator's mouth, it will be eaten. 4 inch shiners will be fish feed with bass around even in the 12 inch range. You probably know this, hence your questioning. There are many experts with a lot of experience here who will likely have some valuable suggestions.
Habitat for the shiners will be key here and, of course, spawning environment. What types of both are available in your pond?
I personally would doubt that 6 pound of either size would be enough, but I'm real new to all this. Let's stay tuned for true words of wisdom...
