I'm inclined to disagree. Most people might follow the same route most of the time, but that's not compulsory except in a few limited instances - usually for a good reason such as minimising erosion or keeping landowners onside. To take the AW as an example - I know four ways up Robinson after leaving the road and at least three different lines off it. I can think of any number of variations on the descent from Dalehead and quite a few different options in the last third of the race as well, until the final flagged descent from Catbells. Yes there is a well defined path for almost the entire route but I frequently find myself on lines quite a bit off it. If you bring in the teenager this adds a lot more sections off paths with route choice involved. So I don't think these can legitimately be described as trail type races, especially if visibility is poor and navigation off path is required. I think they are better described as fell races but with a possibility of following tracks or paths for much of the route if you choose to do so (and don't mind some extra distance/climb maybe)