The attached assembly contains 3 parts modelled in slightly different ways. All parts fail when the dimension of 600 is changed to 200 in the Tool Part, probably because a different face comes into play...but it's the same body.
Can anyone suggest a workflow that would allow parts to update when this type of change is made.
All of your parts are grounded, you should be able to constrain this model with just with constraints.
Create your rectangular hole as one feature and the slot that accommodates the Tool Part as a second adaptive feature using the Project Cut Geometry. Easier if you place this sketch on the "high" side of each part. If you use this projected edge for the top end of your feature it will change with the 200-600 change.
I'm not sure I understand how the rect hole can be created first. The design intent is that the slot matches the height and width of the tool part and the rect hole then sits above it. If you chage the dimenion for height and leave the 600 dim as is you will see how it works (except for part C that will fail due to copy face bug)
Apparently I missed that implied intent in your post, my apologies for not being a mind reader. I'll have to go back and read between the lines.
Only one of the parts was adaptive. Not really sure what your intent was with every grounded as well as constrained.
The parts are were positioned using out of the box Ground and Root component feature, which is perfectly valid where a common origin skeletal work flow using derived parts is used. (and recommended by many who advocate avoiding constraints and adaptivity at all costs)
They are obvioulsy adaptive and related by the fact that the tool part is derived into A & B in the first feature.
Part C has the adaptive glyph because I tried a different approach to see if a bug I reported 3 years ago is fixed - it isnt.