That's not really how the controlled by variable option works, it only shows the values on whatever tab the user meets the criteria to see. So if a user meets the criteria for multiple tabs I believe it will display the contents of the "leftmost" one when viewed in card editor. there is a workaround, but it's pretty messy. You would need to add him to a third group, and create a tab for that with the 2 tab controls on it. So a tab control with 2 tabs inside the tab control that is controlled by group name, hope that makes sense.
I fully understand what you mean and was hoping to avoid going down that road. What I may end up doing is provide the engineers that make drawings an alternate login to access the drafters tab. But that kinda sucks to. The other idea was to tgive hem a unique transition that only they have access to and then write the value to the data card during the transition. I think this is what I am going to do...........maybe.