... No that's even worse - it's somewhere around the middle of the pack for Chrome Wheels because of a few particularly edge focussed things like Killerken, presumably Gargole and Bahamdia (though these are all lighter) but it's still one of the Wider Chrome wheels, the panels are thicker than they look and have a look at the block of metal around the peg hole - not only how much wider it is towards the outer edge but also how much thicker. On the other side, there's the head, and the triangular columns on the inside of the outer edge - all more weight towards the edge. The inner channel goes down most of the way, too. The most comparable thing I can find is probably Libra (mold 3), with the holes in Libra being compensated for by Genbull's greater width. Again, I'd say the horizontal centre of mass or w/e it's called would be at the top of the walls, about half way out.
I disagree on most of those being more edge focussed. Genbull is one of the wider Chrome wheels and it has those triangular columns underneath it around the outer edge which are quite thick, and again, those panels are thicker than they look. A lot of the things you mentioned have large, thick details on their tops - Balro for example has a bunch of thick sections throughout, Revizer is probably a bit more edge focussed, and Wyvang uhhh I don't know if you noticed those struts but there is no way Wyvang is more edge-focussed than Genbull) and Genbull is also a little wider than most of them, even if it is just that outer lip.
You do need to mention the weight distribution, I would say it is unspecialized - neither particularly outward nor particularly compact for a Chrome wheel, but mention when talking about stamina use (obviously keep in mind some parts apply to genbull genbull only) that despite not having a particularly edge focussed (we need a better word for this) weight distribution, genbull genbull's immense weight compared to competitive stamina wheels more than compensates for this given its relatively low recoil and good balance (excellent balance for a synchrome, really). With other chrome/crystal wheels, the distribution is compensated for by its decent balance and the round outer lip which protrudes past a majority of other Chrome Wheels.
If you want more evidence that it's not compact, think about what effect that would have on spin-stealing even with the decent balance and outer lip - think about your MF-M tests, yeah? Balance is good, as is that edge, but your LAD is going to suffer if you're using something that is legitimately compact.