In reply to Wiley:
> Average Distance Per Day: 14 miles.
> Total Hiking Distance: 629 miles.
> Total Driving Distance: 844 miles.
> Total Expedition Distance: 1473 miles.
> I plan to do this as part of a military adventure training expedition, raising money for a forces charity and hopefully promoting the appeal of the British wilderness.
> My reason for posting here is really to ask your opinions, is this achievable? Too easy? Worth it?
I'd start by Quoting Picasso- 'if you know exactly what you are going to do, what is the point in doing it?'
From your post, it sounds like you're uncomfortable with uncertainty. The questions you ask about it being achievable or worth it are really only answerable by you.
It has been said that all expeditions are easy in retrospect.
There are websites such as Walkhighlands, Munromagic, and ScottishHills where people post their trip reports. Often, the reports will have a statistical summary of what their walk entailed. I'm not sure whether individuals provide that information because the layout of the webpage invites it, or because they think it is of interest to others.
Ultimately, it is what matters to you.