I would stick with canned because I think it's healthier than kibble.
Have you tried not just putting the boiled chicken on top of the canned but actually blending it in? If you can't get them to eat canned, there isn't a good chance that they will eat a good amount of kibble. I don't think you can just leave the food down and expect them to eat because they eat just enough to stay alive which isn't healthy... Just my opinion
Then again, I am on the dog's side on this one.
I see no reason to not add at least a little bit of human food to their food to make it taste better. I'm not saying you should homecook... Just that while feeding a dog a little bit of human food could make them picky, as long as they are happy and enjoy their food, there is no reason not to.