CFM i think you are onto somehting there...
madnatory retention of hatchery fish ain''t a bad idea. They do it for the Non-native lake trout in Yellowstone lake that typically eat the native cutthroat..

However i think with such a reg you'd also have to say that a guy has to either quit fishing after he catches his two or three whatever the limit is or he is allowed to C-R after that..