I am cooking two large briskets in the oven at 325 can I cook them at the same time on different shelves of the oven?
I would think that you could, but you'd need to rotate them (changing shelves) three or four times through the course of the cooking. Will probably need a little additional time, as well.
But remember, every time you open the oven door you let all the heat out. The oven then has to re-heat to temp, thus drying out your meat. When the heat leaves, so does any moisture in it.