Can it be done? Should it be done? Civilian Communications are established differently than other services. Law Enforcement, Marine, military, are just some of the things that come to mind. Example of the civilian world is, CB, 40 frequencies and are incapable of communicating with those on any other service. Some FRS radios are capable of using GMRS channels but cannot communicate with anyone on MURS, and Amateur Radio even with all of the things you can do with it, normally can only receive outside of the amateur radio band.
One of the ways to interoperate is to select a service that will give your tribe the best options for your particular situation. Are you going to need extended ranges to get over mountains? How reliable do your communications need to be? Is everyone in your tribe going to need to be licenced or are they more of "the less the Government knows about me the better?"
One of the best services available to us mere mortals is GMRS/FRS. Even though GMRS requires a pay to play license, you don't need to know the difference between a picofarad or microhenry, or what a resistor or inductor vs conductor etcetera. GMRS does allow you to use a repeater to extend the distance of your GMRS radio, and with it being shared with the FRS service, your tribe can establish a pretty sweet set-up.