Vandam isn't that good, it starts off at the beginning of G3 ranks after all. But it was made by a brilliant creator who said that this one unit could cause the evolution of MPIS via the Invent System.
Even if its just a scrap of intel on the unit, other countries would kill for such a device. Which is why it occurred to me that Tatenashi might send Irish in to grab intel. He then turns his attention to the Kingdom of Ea for being the embodiment of everything he hates.