Interesting decision to send a C17 as opposed to a Voyager.
1. There's a big difference between an advertized A330MRTT medevac capability using Airbus proprietary medevac systems and a proven medevac capability using several different off the shelf medevac systems offered by many different companies.
2. Loading stretcher patients in a C-17 does not require a high-lift loader like the A330.
3. Loading stretcher patients in an A330MRTT without a freighter door (which the Voyager does not have) is VERY difficult. A330MRTTs with no freighter door can essentially only handle ambulatory medevac patients.