For the shiners to have any chance of becoming a reproducing, regenerating forage fish, they will need a lot of weed cover to avoid predation. In my pond, they have survived in naiad, I believe, and American pond weeed.

But, I do stock about a hundred lbs. each year, and sometimes twice a year (sometimes mixing between fatheads and golden shiners). I do this mainly because when the fish truck comes, you might as well load up.

Regarding the walleyes, I put some (20) or so in my pond about 3-4 years ago. They were around 10-12 when stocked. I occasionally catch a walleye, and they might be 14-15" tops now. They are also not that fat even though there is plenty of forage in the pond.

I think your existing catfish and bass will put a hurt on any walleyes that you stock. Maybe plan on a predetermined mortality rate for the walleyes so you stock enough to enjoy them.

Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."