Taking Attache as a Veteran advance

Someone asked if they could take attache as a veteran advance. And I didn’t see a reason why not other than the extra text below attache that specifically mentions that a Medic can be assigned to a mission regardless of the number of specialists on the mission.

So I thought I’d pose the question here! Is this something that a specialist can do? Is this something the designers intended or was this overlooked? Thanks in advance!

Fiction first. Do you think it would be fictional weird? Don’t allow it.

Can you players find a good fictional way to justify it? It’s their job, not yours. If yes, allow it.