I'm going to jump on here and say that, even with the RNG, a lot of builds are just...not viable, which is sad. For example, the "Take one second off the pistol to the left/right" pistols are impossible to make into a winning build. That's sad, since they are among the coolest.
I even tried putting those two pistols facing each other with multiple ".5 seconds off pistol charge time" blocks, but no luck.
I think you should consider rebalancing if you have time. Like, if a player gets perfect RNG and draws four pistols (two "left" and two "right") and four "-.5" blocks, they should be easily able to beat the later enemies.
Edit: Welp, I guess it was a skill issue (or a need for luck), because I've won the last few games in a row using fire, pistol, rust, and of course melee. I believe I've done Shock, though it was super hard.
Cannon and Grenades seem impossible right now, and many of the "Unique" and "Exceptional" items seem almost impossible to use, even if you're lucky. The upgraded Superior weapons are generally better than the Unique weapons, I think. Some tinkering might make those cool end-game weapons a bit more usable.
I would call this a "fake" cannon victory. I was able to beat launcher spider, but I used a melee build to beat every other battle.
)