How do I cook large quantities of Boston pork butt?
You can keep them together, but I would recommend budgeting a very long time for cooking. In my opinion, your better bet would be to slow roast them in the oven, with some air space between the two roasts. I would also consider cutting each roast in half. Four 7-8 pound pork butts will cook much faster than two 15-16 pound ones.