Basically, the way I see it is this: in custom games, where you choose your demigod before hand, obviously the person going to random is going to know what the other people are, because he saw it in the battleroom before hand. For the others to not know the random faction until the random is scouted, makes sense.
For ranked, the idea that one person can see a demigod and the other can't, before either one has been scouted. I hated everything about the scoreboard in supcom, because it showed faction before hand, gave away bs info, etc. The way I see it, whatever in game player indicator Demigod has should be fairly similar to TA's: it shows the color and name of each player, and maybe some innocuous stat (in TA, it was kills/losses). That's it. So in automatch, no one would know what their opponent is until they encounter him on the battlefield.
Even then, random still gets that same advantage, just to a lesser degree. If I become a "top player" in Demigod, and it's well known that I use Sedna exclusively (much as it was well known that, say, Scyn used Seraphim exclusively), and you play random, you still have that same advantage, it's just not given away by the game.
Basically: I hate the idea that any info at all, whether I'm random or not, is given to my opponent in an automatch.