Yes but that's not the point. You are telling what the game allows to do, and I'm saying what many people usually do, and the impact it has on the completion of missions.
The actual vehicle is not required, the game alerts you to a personnel requirement.
On the screenshot I posted above it indicates personnel.
On the red banner, it will say "Missing Personnel: 2 x Mobile Command"
A lot of people will place their EMS Mobile Command Personnel on the EMS Chief vehicle and not utilise EMS Mobile Command vehicles. It comes down to personal preference and build style.