Hi Tom
The easy bit first. Yes it certainly can be done without a guide using only the map (and compass if you really need one).
The route is very obvious 99% of the way if you utilise the new surfaced route that avoids 'The Bog'. Unfortunately the new route has yet to show up on the current OS map as a Right of Way (green dashes) but a general idea of the route can be seen if you follow the Pennine Way off PyG to Tarn Bar then you will see an indicated path shown as ----------- running up Whitber Hill, crossing Sell Gill Beck & Sell Gill Hill to re-join the Pennine Way south west of Jackdaw Hill. This route is now well surfaced and waymarked. (If you haven't physically got the OS map you can view the route on
http://maps.northyorks.gov.uk/connect/)
With map in hand and a copy of 'The Guide' I would find it incredibly difficult to see how anyone can get lost if using this route (I've had people email me to say they've used 'The Guide' throughout the route and never had to even consult the map).
Crossing 'The Bog' may be a different issue and it's far more difficult to convey/predict an exact route as it's so dependent on the prevailing weather conditions and on how much you need to detour around it. It's covered in 'The Guide' and with relevant OS reference points but if I was sending 50 people over the route I'd avoid 'The Bog'.
Wouldn't bother with the video, there's plenty of video's on Youtube to give you a flavour of the walk.
The information r.e. maps is in 'The Guide'.
Organising for a party of 50 people surely isn't impossible but will take a deal of planning and discipline. If you're taking 50 people on a 25 mile hike I don't believe one single person can 'lead' the whole group.
I've certainly never guided that many people across the route, my max is 12, but even in a group of 12 it becomes apparent very soon on the walk that people will travel at different speeds. If you're intending to stay together as a single, albeit large, group it will take a lot of discipline from the faster walkers to keep to the main body of the group. In reality what happens is that the faster walkers get ahead and eventually get frustrated in waiting for the less speedy walkers, who, get distressed as they feel they are holding the faster walkers up and try to push themselves a bit more and therefore get more fatigued.
If this is a 'team building' exercise is there any intention of some people providing ground support? E.g. If any of the team are unable/incapable/unwilling to take on the challenge would they be likely to provide logistic support at identified spots (food/fluid/medical provisions etc)? Or is everyone being expected to pack all the days provisions in their backpack?
What time of year will the 'event' be held, will it be a weekend attempt or a mid-week one? What age ranges have you got? Have people got the right equipment? Will they train for the challenge (OK if you're in the 18-30 club you probably wont need to but if your in the 40+ club you might need to get some decent walking in before attempting the challenge).
And I've only just started ..............................