Well in the official fiction, the UNE bought a number of BAPs, which turned out to be popular with pilots due to the roomy interior (and presumably the obscene firepower). These guys look to me like an Earth military contractor either subcontracting to Infranite tribal interests for a cheaper, mass-produced BAP, or licensing BAP tech to produce a Behemoth ASP replacement better suited to long stints "in the saddle", longer operations in non-hostile environments where the ASP would get claustrophobic, and the like.
And yeah, I'm buying some in 28mm if he funds, because I want a light mech in-between the Behemoth and the Superfortress for my UNE-in-DefianceVG army.