In reply to Andy Moles:
Sgurr a' Bhasteir is probably an outlier in more than one way as it was an extra top added during the second completion (I think as a bonus after being faster on the ridge than expected!). It's a nice addition and conveniently rounds the number of tops up to 60, but maybe breaks slightly from the logic of the rest of the route.
The line otherwise sticks to the ridge crest, apart from diversions for Munros/Munro Tops.
Would be fun to see a linkup some day that takes in a few more of the outliers from the main ridge - Thuilm, Third Pinnacle, Fheadain, Coire an Lochain, Dubh Beag, etc.