"former special force", "flew to expert across Europe for testing and trial"

Yeah this is not your average mountain climber group, "normal" people could not do this just by xenon gas alone

Yeah was about to say that must have been really good baseline fitness.

I know people that made it to Kilimanjaro as pretty average middle class urbanites with no substantial climbing background, but that's probably at the edge of what's possible.

> I know people that made it to Kilimanjaro ... with no substantial climbing background

Kilimanjaro is an arduous hike. No technical knowledge or equipment is required. The main challenge on the mountain is altitude, which is countered by time spent acclimatising.

Yeah, I knew some middle-aged marathoners who freely confessed that Kilimanjaro kicked their butts. As you say, it's not a technically challenging climb; it's just a long, long hike uphill in steadily thinning air.