Ok I have figured out where I was going wrong - Note to self... staring at the computer screen and begging it to work doesn't work!!
What does work is to make sure the fields on the layout are the from the correct TO
The TO for "Positions" has the fields you want to populate using your Value Lists so you need to use the matchfield fields that are in the "Positions" TO and attach your Value Lists to them.
So simple but sometimes we can't see the forest for the trees!