I get most of what has been discussed however when hewing a cruck blade - these will not roll in the same way as a straight log and hence another method is needed to raise the log. I have noted in our woodland that we have a long rectangular shallow pit close by to our saw pit. This pit is only about 2 foot deep and I wonder if this was used by the hewer to roll the log over on bearers and then to stand in the pit / trench rather than raise the log. This method however does have the downside that the log needs to be moved to the hewing pit and without heavy lifting gear that could be quite a task and also embed stones and cover the log with mud which not good for sawing or hewing.
Cruck blades would appear to be converted by a combination of hewing and sawing.
Ken Hume