I thought this would be an interesting topic, as there do seem to be multiple examples of this in the movie. I was prompted to start this topic because there seem to be some actions or events that are solely attributed to Jack's initiation of them - it is my contention though that there are instances in which Ennis helped to 'set the stage' so to speak, thus being the true initiator, or precipitator of some events or of some of Jack's (re)actions.
I would like to start off with an observation of pre-TS1, after now viewing BBM half-a-dozen times. I am leaning towards the perception that it was actually Ennis who initiated his own invitation into the tent by his 'hammering'. I cannot say that Ennis was clearly formulating this in his mind, but at some level, he must have 'known' that if he kept up his hammering long enough and loud enough, he would get another invite by Jack to come into the tent....again, I cannot say he was consciously planning this or what was to follow, but I do believe that he might have hoped for another invite from Jack to come into the tent.
I look forward to the group's comments and insights