A tweak for walleye -
Don't think that walleye are the world's most finicky line shy fish. I have discovered this year that when fish are lethargic or non-aggressive, either because of water temp (either too hot or too cold) or an over-abundance of forage, a short leader will out produce a longer one.
Sluggish fish will swipe and miss bait a lot, and a minnow on a lead that is over about a foot long can escape them and they will not follow often. But, if the minnow can only move a couple of inches, that same non-pursuing fish can get two three or more swipes at the bait without exerting significantly more effort.
Kind of un-related, but right now I am getting walleye and 6" leaders or less to 1/2 ounce sinkers - I know that those fish can see that sinker, but they don't seem to mind, because their laziness is trumping their concern about the sinker.
Got interested in this theory by watching videos of a guy who fed a camera down his line to the sinker - the fish would bite with the camera less than a foot away from the bait...