The grab and go section is a healthy extra b
You couldn't have say 2 slices of bread as your b choice, and then something from grab & go (I think 2 weetabix is in that list? I only ever have hifi bars as my b choice so I forget what's there lol)
Yes if you have 2 slices of bread as your b choice, you could syn anything else you have from those lists. You're looking at an average of 6 Syns for each item