I.m sure it can be done. Maybe a reskin of the Deputy with the traffic vest on. (I heard that reskining personal is a pain) A Sargent? You could make a copy of the Deputy and have him spawn in at the beginning of the game. Just edit the commands of this guy to equip/shoot/etc. Atleast that is what I would try.
I am not sure of this but you will most likely need to divide the bay into 2 separate Virtual Objects(Name them accordingly) then edit LABattalionChief, LAFireStation, and LAFireStationStart scripts.
If that did happen the mod name may need to be changed to "US Miltary Mod". Then you can have all branches included as well as more maps. Like a jungle map as well as perhaps a more city looking map (Like Dubui)
1. Is the installer present? If not I think it is posible to manully install games mainly because installers just unpack files and move them to a specific directory Ex. [C:\Program Files\Sixteen Tons Entertainment\Emergency 4\Data\] the application is looking for specific files from [C:\Program Files\Sixteen Tons Entertainment\Emergency 4\Data\] BUT if it is installed into [C:\Program Files (x86)\Sixteen Tons Entertainment\Emergency 4\Data\] the application will not be able to find it therefore it won't be installed right.* [] Sperates directories from the rest of the text. *I'm not sure if this is right but this is what I've noticed from person experience.