This formation is the 'Embrace of Nayári' (the base dimensions are in red). The ends of this unit project forward, and are meant to penetrate into or envelop an opponent.
'Blade of the Sword', a formation that has few ranks, intended to cover a wide frontage.
'Garment of Idéssa', a checkerboard or quinqunx-style formation. This one is a bit harder to portray on the Impetus bases, but maybe two bases in a Large Unit group would look better.
'Stone Mountain', your typical wargaming unit formation. I will probably reserve this formation to those units that are armed with pikes, to help alleviate any confusion with long spear-armed units.
'Teeth of Krá', where the unit is formed into wedges, in order to penetrate the opposing formation. This array, along with the 'Garment of Idéssa' above, are two types of formations that would never be used by the non-human Shén or Ahoggyá, who liken these fancy displays to 'silly human folk dancing'.
There is one other formation, preferred by Livyáni forces, that is a single large wedge. It is too large for a single base, but, if I ever procure a Livyáni force, could be represented by two bases paired as a single Large Unit. There is also one formation that would look best for missile troops; when I have a unit of archers ready I will use that at least once.