Improvement to ugly graphic

Information for the business: Military medicine research
Industry: Healthcare
Design details: Hi! I'm a medical researcher in need of a graphic representation of medical care capabilities in the US/NATO Allies military system (ex: medical tent in combat zone v. giant hospital in Germany). I need a better looking version of the attached graphic that conveys the information in a cleaner and more polished presentation. It needs to represent the level of medical care capability available at various levels of field hospitals. I do not have de-novo graphics to provide, but I'm open to anything you use as long as it's contextually relevant. The point is to have a reference for what types of care are needed, so I can later draw arrows to different projects that fit in different levels (ex: brain injury questionnaire in tent v. MRI in giant hospital)
Target audience: Military scientist and doctors
Ideas for the visual style: Serious and professional, very clean.
Things to avoid: cartoonish-ness,
Preferred colors: Military drabs.
Urls to draw inspiration from: https://www.nap.edu/openbook/23511/xhtml/images/p-140-1.jpg
Where the design will be used: Website (under development)
Extra notes: The "seabase" graphic is an example of how the main graphic could be improved. Margins with information on each role, leaving the central region largely graphical with minimal text. Just a suggestion/starting point.

IF YOU WANT/NEED TO learn more about the content in order to do more accurate work, here is are some links:
https://www.nap.edu/read/23511/chapter/6#105