I commented in your first post on this topic but I'll copy it to here as well.
Interesting that the raw and kibble together controversy has come up here. It's being discussed on another forum I visit and no one can come up with any science to back up the notion that they are bad together. Certainly the idea that they digest at different rates and that one holds up the other is disputed. Several folks seem to be feeding raw and kibble in the same meal just fine. I think it's going to be like corn in dog food, OK for some, not for others. Or the notion of switching foods gradually, again, required for some, not for others.
The info. posted above on what people "heard" and "read" is what I have encountered as well. Though I have since found several sites that state the idea of different rates of digestion somehow holding up one (or the other) component of the food is "nonsense" and a "myth". Neither side has been backed by research by someone accredited to do so. I'm going to look into Rainbow's source of information as soon as I can.