Well, couple of points here.
As you explain, even in Solo, AEDC still can't win, because CODE are playing in virtual solo, because AEDC can't see them, and are neutralizing their effort. So, it's not really unfair. It may be deeply
unsatisfying for those imagining epic space battles, which you anyway recognize that you won't get, as 32 is not really an epic number, but it's not unfair, which has been the argument thrown at Group and Solo mode for a while.
As I said in a previous post, for those who genuinely want more players in Open, you need to make it a compelling place for players who don't actually want to be there, and giving more credits and the like just won't do it. I don't have the answer for you, I don't wish to engage in non consensual PvP, so I cannot imagine anything you telling me will make me want to play Open, but I think you might want to try some positive marketing to the undecided (if there are any).
PS. And this is not aimed at you, because you don't do it, but for those that do, calling players who choose to play Solo or Group scared, cowards, not man enough et al will probably not win over that many hearts and minds.