Cooking pizzas using two stones/steel vs one stone/steel in consumer oven
Having 2 stones/steels in the oven is totally workable, the top one would cook a bit faster than the bottom one but that's not a dealbreaker. 2 steels will take longer to get up to temperature than one, whether an hour is enough in your oven is not something I could say. I would suggest you get an infrared thermometer so you can take measurements and know for sure, they are cheap and take the guesswork out of it.