Scale indeed matters but you can use this to your advantage another way. I use the Lodge Cast Iron Combo Cooker that Robertson recommended in Tartine. The confined space means you need very water to create an appropriate amount of steam. I have found the water coming off the dough as it bakes to be sufficient, but a very small amount of ice can always be tossed in just before covering. The cooker is enclosed so you don't loose steam if you have a gas oven like mine that vents and makes conventional steaming more or less futile. And of course, that mass of cast iron all around the dough pounds radiant heat into the dough like a boss.

I ordered the combo cooker and a cast iron pizza pan from Amazon. This ridiculously heavy parcel shipped free. Life is grand.