Question about the Roman \'wedge formation\'

[Dithrambus]

While this has become an interesting conversation and I thank each of you for your insightful responses, I am having difficulty determining the general consensus. Perhaps I should also apologize for my use of a made-up term: 'sawtooth' was simply the only phrase I could think of to describe what I had seen in the documentary. I am familiar with the 'boars head' or single mass wedge formation, it is the use of multiple wedges across the front line that seemed odd (at least to me). The documentary also seems to conflict with itself because the Romans are depicted in a typical line formation with the front rankers alternating I believe every six minutes and without much explanation they are depicted in the multiple wedge form, I do understand that the 'boars head' was used to break an enemy line, however if the Celts were already 'broken' so to speak, then I had assumed this was simply a 'killing machine' ('Mill of Ares' to us hoplites :wink: ) to finish the gruesome task. It is also quite possible that I have missed a point or two along the way :? To be more direct, am I to understand that this formation is simply theoretical? Or is there classical literary reference to it's use?