ORIGINAL: Taxman66
PvtBen is saying 1 DE, and when it comes time to deploy the AK just restrict the deploy-able hexes (like when various other event based units show up) to all the possible spots (i.e. Near Benghazi, Near Tripoli, Near Trieste, and added near Berlin) and let the Axis player then pick and choose. Obviously spots that are under Allied control will not be available.
This is probably the easiest and best solution.
I don't think that's possible in this situation. Even if it was, it would mean the player can spread the DAK across all 4 locations. That might not be an issue for simple player choice but it would reduce the historical accuracy of having a DAK, especially if it never arrives in Afrika!

To make sure the DAK arrives in a single location out of the 4, multiple DEs are needed tied to unit.txt events. Even though multiple #RESOURCE_LOCATIONS= can be set in a single unit.txt event, the system chooses the first one to use and then we're back where we started.
(like when various other event based units show up) - which ones are you thinking of?