I found the documentation for importing site definitions in DCRUM. You can take a look here to learn more about what its capabilities are:
Not sure what limitations you are referring to, but once you understand the hierarchy, that is probably the biggest limitation.
Site are group into areas, which are group into regions. Depending on where your sites are and more importantly how you want to report on them, you can use these three groupings to solve your business case.
Ex. You are a global company, and want to report based on region, country, and sites within the country or region. This would follow the standard model and your regions would be something like: APAC, EMEA, and Americas... countries would be self explanatory... and sites would be your lowest level calling out each office location.
Ex. 2. Your company footprint is small geographically and you only have a few office in the UK.
Region might be the office itself,
Area now could represent the floor that user is on
Site could be the type of user on that floor (guest, wired, wireless)
Some of this would depend on how well defined your DHCP scopes are set as well.
Ex. 3 You have a company footprint that is spread out across geographies but your reporting is focused on business unit because you are an umbrella company with many sub-brands below you.
Region might be each brand
Area might be the country
Site is still site
Hope that makes sense!