Contact list of users

Hi, We are currently creating a sheet/form for staff to submit a trip plan. This requires noting each staff member travelling in the vehicle so a new column for each staff, which then pulls through their emergency contact information.

At the moment, for each column, I am having to add the staff names to the contact list so they are available to select from the drop down. They are users, so I have to just select each name. However this means every time we get a new staff member or someone leaves I would have to go through every column and add/remove.

Is there a way the contact list column type can automatically lookup the users in our organisation? I should be able to say 'contact list' type then opt to add all organisational users so as we have staffing changes the list is updated.