If it wasn't for a small matter of a wall and a couple of trees you could give the pure 'down and up' route a go compared to the contouring. Eg follow the track to 670197 and then straight to path junction at 674200, and up Aggies Staircase.

But as I say, small matter of a wall(s) and a few trees. Although there do appear to be a few tracks/trods on that piece of access land when viewed on google.

Comparing the two routes after having plotted them on 'where's the path' , T'Y's route to the top of Aggies came out at 1.12m and an ascent of 62 metres, the 'bee-line' route came out as 0.66m and an ascent of 52 metres. Shame about the wall, know which way I'd choose!!

TF