John Matrix is an Agent.The name is kind of a giveaway, but... bullets can't hurt him. The laws of physics mean nothing to him. And he really, really, doesn't want Sully to use that phone booth. Whether he's an Agent who's gone rogue after becoming attached to his "child" (a sub-programme he created from his own code), or Arius is really an earlier iteration of The One (with Bennett as his equivalent of Morpheus) remains unclear.
The T-800 models were designed to look like John MatrixSkynet intentionally designed them to look like a soldier with a badass reputation in an attempt to make it easier for them to infiltrate the resistance. Seriously,if you were fighting a war against literal death-machines and a man with a reputation for overthrowing dictator's regimes shows up aren't you going to let him join in the fight?
John Matrix is the reincarnation of Conan of CimmeriaReincarnation was a heavy topic in the original Conan stories, and they look and act exactly the same. coincidence? I think not
Commando is set in the same universe as Die HardVal Verde exists in both movies. In fact, Die Hard was originally conceived as a sequel to Commando. By extension, according to The Other Wiki's article, this puts Predator, Supercarrier, Adventure Inc. and Jurassic Attack all in the same 'verse.
Bennett was kicked out of the military for being gay.When he sees Matrix, he talks about how he's pissed at John for getting him kicked out of his old unit. Considering that the movie is set about three decades before Don't Ask Don't Tell was repealed, and also how Ho Yay Bennett is throughout the whole thing, it's not much of a stretch.
- Except that John states that Bennett was kicked out for enjoying killing a little too much. Of course, this probably sets him up better as a Combat Sadomasochist.
Commando is set in the Metal Gear universe.Matrix's old unit, was in fact FOXHOUND. Since they all got killed by the mooks hired by Arius and Matrix went back into retirement, there's little left of the unit. Since Commando is presumably set in the then-present-day, Big Boss comes back after the end of Metal Gear Solid V: The Phantom Pain and retakes command of the unit and builds it up again bringing in Gray Fox and others.
"John Matrix" is a nom de guerre.It's just such an obviously too-cool name. Arnold's character was in covert operations. Such people are undercover, which must include keeping one's real identity secret. So whoever this East German man really is or was has been erased, and (by himself or with the assistance of whatever military entity he was a part of) he has assumed the pseudonym "John Matrix" to protect himself and his family, probably right when he was recruited into covert ops.