Thanks for the reply, and for making a fun game! The top to bottom, left to right thing is what I eventually figured out and it works ~90% of the time, but it definitely doesn't work 100% of the time; good to hear that's a glitch. I've not seen a golem chain propagate right to left in a single block, but I've seen it trigger the bottom golem first several times. Is there a chance rotation might be messing with it? I don't think it's happened when I've not rotated a block but I suspect that's just a coincidence or it would be happening a lot more.
Also I just found legion for the first time and it doesn't work with Golem (and I'm guessing other on-place effects either, since doppelgangers don't grant turns when becoming clocktowers but do cost turns to remove). Also if you get two or more level ups simultaneously, like for example by playing legion on a hellfire or other high-value card while having lots of available blood river space, the animation plays several times but you only get one level up, at least if you decline a card.