an excerpt from the MLTE page for those who don't know:
Not sure whether to choose ML or WGL? Think of WGL as ML without the wild camping, the movement on steep ground or the ropework. The standard of navigation is the same but does not involve steep or rocky terrain. You are expected to navigate with the same accuracy as for ML but over terrain known variously as moorland, hill, fell, bog or down. The terrain is well defined by obvious boundaries, such as roads and coastlines.
Walking Group Leader Award – further information This award is for leaders of walking groups in non-mountainous hilly terrain, known variously as upland, moor, bog, hill, fell or down. Such areas are often subject to extreme weather conditions and require an element of self-sufficiency. The scheme seeks to develop the skills necessary to lead walking groups in these areas.
Leaders seeking to take groups into mountain terrain should register for the ML Award, although the WGL Award can be a valuable stepping stone for those wishing to progress to the ML scheme.
So, WGL country isn't necessarily 'lowland' you could be on a high plateau - and definitely not farmland (well, no more than ML would be e.g. during course or assessment we only went through farmland to get to the open country).
I'd say, if you haven't got the logbook days already, and aren't sure how long until you will go for ML assessment (could take some time due to needing to get your logbook filled) then consider doing the WGL course as a taster. It's only 3 days and will get you familiarised with the Nav/Group management levels required of both awards.
I needed an Leadership qualification for one of my jobs (Youth Work on Dartmoor ). So I did a WGL. I don't intend to lead groups in ML country and am happy with all the ML practice except ropework really. And like most hillwalkers I don't use ropework as part of my hillwalking . Also time cost were a consideration - courses/assessment was paid forbut time off wasn't.
For my Logbook, due to the fact that most of my non-Dartmoor Hill Days had been in 'ML terrain' not WGL, those days were accepted for WGL - as you need experience on quite a few areas. (though I have well over 400 Dartmoor days)
On the course: There were 6 of us. I would say that 4 of the 6 were quite surprised at the level of navigational competence needed, and had to work hard due to some of it being new knowledge.
I found it a welcome refresher and have polished my nav practice since - I'd been adequate before (been a selfsufficient hill navigator since 1984) but am much more 'precise' all the time now even when not leading (unless just having a random wander).
I did the assessment 2 months later in February. There were 4 of us. 2 had done the ML training course, not WGL. I'm pretty certain that one of the ML trained people failed on nav. (I wouldn't have wanted him leading me in poor conditions...).
Funnily enough, due to funding issues I've never needed my WGL for that job! But have been able to help train our Explorer Scouts teams for Ten Tors for the last 2 seasons, which is very rewarding.