Interesting. What I see is Brookes doing what he often does, which is to amble pointlessly. As long as a player can get a few inches from him, they can run round him. He tackles best when someone runs directly at him. Compare that to the work rate of some of our other more mobile props.
But, to the point of the video, it is about taking advantage of the gaps made by the defence.
I don't think Brookes quite ambles pointlessly, he's clearly doing the "right" thing by wrapping around. He just doesn't seem to engage his brain constantly. He does what he's supposed to do, but keeps doing it until he arrives, ignoring the fact that the game is evolving in the meantime.
I think it was Gloucester where Robson put in a kick, and Glaws ran it straight back and scored. The kick was OK, the huge hole was caused by Brookes not looking at what was going on, just jogging up in the defensive line, without realising that he was 10m+ from someone on the other side, and Glaws were running it back. I think he only looked up after the glaws player was 10/20m closer and already halfway through the gap, had he been actually looking up, that hole would have been a lot smaller.