I'm using the archetypes / org. structure attached.
Import the archetypes.
Upload + recompute the org. structure to have archetypeRef in all of them!!
Go to Org. tree - Example, Inc. - Functional Structure.
Go to Executive Division.
Click New Assignment button, select third one - Assign Organization type member with Member relation.
This should only allow assignment of organization with Organization archetype, but the popup shows all of them.
I seem to remember this worked for 4.0.x before - we have this in training.