I've always thought it clever. The way I learned BT back in the day was that one person generally negotiated for the entire contract (usually the merc commander); and then the rest of the officers signed off on anything required to say they agreed.
In MekHQ, I have one each of Admin/Logistics, Admin/Command, and Admin/Transport. Usually the one that showed up with the best admin and negotiation skills in the hiring halls. That way I control which one is doing the contract negotiations for each area. Since I can only have one of each, all others become Admin/HR.
I think if you are using the CO method of tracking the dragoons rating, you have to have a higher number of admin personnel anyway. And, until this latest release (MekHQ 43.4), I never saw Admin/HR for hire in the personnel market. That was my reasoning behind being able to change admin types.