- It's possible that either Longhena was a former EVAC executive member (or even the CEO of EVAC), or EVAC provided the resources for his army. It's also possible that DOOM was a prototype of the technology that would later be used to create Hibachi (Or Hibachi was being made at the same time as DOOM), and EVAC reverse-engineered Hibachi to make another DOOM.
- Considering DoDonPachi Maximum has both EVAC and content from DoDonPachi DaiFukkatsu, it's practically a given that EVAC was in the background of the DoDonPachi games (At least until DaiFukkatsu), especially since it's canon that the enemies fought in DoDonPachi were developed by EVAC.
And if Maximum is canon, it's shown that training simulators exist and can potentially be just as effective in training pilots to take on entire armies who spew out oceans of Bullet Hell...but in terms of combat prowess. Teaching pilots of DonPachi Squadron to fight effectively through a simulator in which no actual lives are lost isn't enough, they also need to be trained to not care who's on the other side, only that they're targets who must be destroyed, period. What better way to train that mindset by making them fight their friends with deadly intentions until they no longer see those friends as such?