So I cut them back to one feeding a day and we instantly went to all raw food. No more cans, no more stinky food.
The preferences that the cats show for meats are pretty funny. One loves chicke, likes beef, and will eat pretty much anything in front of him that he's seen at least twice. The other loves rabbit, duck, and anything that's mixed with the rabbit so long as it doesn't dilute the rabbit too much (there's a specific ratio that's acceptable).
Since they've been eating meat only (with some supplements, but those really don't count), I've been a little paranoid about their teeth. It appears that my fears are well founded because my little white monkey has one tooth that's covered in plaque. Yes, she lets me check her teeth. No, she doesn't like it. No, she doesn't have a choice about it.
Anyway, tonight I'm going to try introducing bone to the meal. They're both eating chunks of bird now, with the addition and success of the duck last night, and bird ribs are the easiest for kitties to chew. So tonight there will be real carnivore action at dinner. Hopefully, there won't be any growling.