[FULL GAME SPOILERS] Who were the Monsters?

[humanoid]

After watching the Soma Transmission #3 video I get the feeling that Nr2 (Discoball head) is supposed to be Adam Golaski (the guy who appears in the video and drinks structure gel in the end) since
1) the video is set in Lambda station where we encounter the monster first and
2) there is a message in Theta mentioning some kind of incident in Lambda where WAU apparently changed and rebuilt the "h_" (I'm guessing he wanted to write human body/mind or just head?)

Of course I'm not sure if these videos can be considered canon (at least the intro says "inspired by SOMA" but this assumption is also somewhat backed up by the discussion that I found here (first few posts).
Can't remember if he gets mentioned at one point in the game though (perhaps in some audio logs?)

My guess on this is that WAU activated the suit, filled it with structure gel, and it took about a day to get everything ready and upload Yoshida's memory into it. From that point it reads as Yoshida. There may be no corpse inside at all.

That could be too, its very hard to make out if there is any flesh inside that suit or if its all WAU/mutated structure gel, even from the modelviewer (though the lack of flesh makes me think that your theory is more likely).