We seem to have a workable system. With two groups, each of whom get their own food, it's easy - Samson outside and the cats inside. Adding Faldo (who gets his own food, not Samson's or the cats) looked like a problem. But his own routine (outside for a run first, then in for food, then back out) fits well into this.
First, put both dogs out and get Samson's bowl. Then feed the cats inside, and prepare the dogs' two bowls.
Call Faldo in and keep Samson out, and make them both sit and stay while I put Samson's bowl in his kennel. Release both of them to their food.
Once Faldo's finished, keep him from the cats until Samson's finished his food, and then put him back out.
When the cats have finished, let both dogs in and watch as the cats flee from the advancing hordes...
Jasper seems relieved that we've got the Right Dog back. Smokey doesn't believe we can have been so stupid as to get another dog... All other cats seem indifferent.