I honestly didn't think to shoot at the widest aperture, I kind of hovered around f8 as at the time I wasn't too concerned about it - But now that you've pointed it out it makes sense.
We positioned ourselves at the one end of the arena, at the furthest point from us you had the activities in picture one, once they had cut through the log then their team member would continue in the centre of the arena - I've just noticed I've not posted pictures of this, however, once they had cut through their log then the third team mate would continue closest to us in picture two.
We could have definitely moved around which admittedly we should have done, at least we would have had shots from each side - As you've said, the back of someone isn't that interesting.
One very annoying thing, wherever we moved the chap in the next picture would walk into our shot and block most of the view - He was definitely doing this on purpose, at one point he put his boot up on the wood and was looking at us with events going on behind him.

Thank you for the input so far, this is all information I have to take on board and consider and remember when I'm out shooting.
I have more pictures with the subject facing towards me, if anyone is interested in seeing these please let me know and I'll add to the thread.
Thank You