Wow. Seriously? The enemy island values are fixed based on the level and the generation is completely random? That's astonishing. It really goes to show how eagerly the human mind assigns value to random noise. I was so sure adding a shield caused the opponents to get shields early, for example. Now that I know that's not the case, let me play some more and see how I feel about the experience. I was second-guessing things that weren't an issue.
That said, RNG shouldn't make it impossible to win. (Yes, even in a roguelike, assuming progression or learning the game's systems aren't a deliberate part of the intended player experience.) Just about the only mechanic I didn't learn on my first run that reached stage 8 was that those energy weapons that bypass shields are probably what I need in order to stand a chance against the last boss. (Later on, I sort of guessed that you might be doing the FTL thing of a weapon type being impractical and under-powered most of the game but then pretty much necessary for the last boss, but I haven't made it to the end since then.)