A very stripped down way to look at it is you should throw a putter whenever you can, if you can't reach it with a putter next look at your mid, if you can't reach it with your mid next look at your fariway driver, if you can't reach it with your fairway driver consdier a distance driver (which the Valk is). In other words, always throw the slowest disc you can.
I couldn't agree with you more...unless wind is involved, but as you said, it is a very stripped down look at it.