Royal Felines Update
Tonight, I got a better look at just how much food IS in half-a-can of this cat food. Looks like they DID eat at least some of yesterday's fare. Not enough to suit me, but some.
This time around, since the food in question was little chicken cubes in gravy, I mixed the kibble in from the outset. I figured that the gravy would soften it up, and the kibble would impart the familiar scent of the food that Captain and Stanley are looking for. If they consume more of everything that way, win/win.
I put the bowls down and told the cats, "EAT. I want to see these dishes empty tomorrow."
So now we'll see what happens.