Okay, got a clearer picture.
Two butts cook more quickly than one big butt(shoulder)/picnic still intact. Below I refer to one butt basically. You do the same thing for two butts.
I haven't really noticed a difference in the amount of time a boneless takes to cook, compared to bone-in. The nice thing about bone-in is the bone is like a pop-up indicator on a turkey; it will indicate when it is done. When you can wiggle the bone and it feels loose, the butt is done.
Temp: forget about 200F chamber temp. With the timing you're looking at, aim for 250F, and be ready to bump to 275F if you start running short of time. If the butt finishes sooner than expected, that's absolutely no problem. Finishing later than expected, ALWAYS a problem.
Wrap or no wrap at the stall? Wrapping with a little hot apple juice (nuke the juice in the microwave), speeds the butt through the stall but gives a soft bark. You'll get great smoky flavor but a soft bark. If you want a firmer bark, but still want to speed up the finishing time, wait to wrap it at at 180F internal temp. If you want a crunchy bark, don't wrap at all, but it takes longer. I don't know what smoker you're using, MES maxes out at 275F, others can go higher. Once the meat is through the stall, crank the smoker up. A butt can handle it.
When is it done? Internal temp is an indicator. Aim for 205-207F, but wiggle the bone and poke it with a probe, like a two pronged fork or instant read thermometer. When it slides in easily, it is done. If you feel resistance, keep smoking.
Rest: wrap it in foil, then cover it with clean, old towels or put it in an empty cooler. I like to let butts rest for 2-3 hours, but one hour minimum.
Serve: Save the juice in the foil wrapper if you wrap it. Add it back to the meat after you pull it apart. If the butt tastes a little flat, add more of the rub you used. Some people like to add BBQ sauce. All it takes is a little if you're going to do that. Personally, I serve BBQ sauce and Chef JJ's finishing sauce on the side, telling people to try the finishing sauce first before they add any BBQ sauce. It is the rare person who adds BBQ sauce after trying Chef JJ's finishing sauce. You can whip up the finishing sauce in mere minutes. Recipe is below.
Have fun!
Ray
http://www.smokingmeatforums.com/t/122319/jjs-finishing-sauce-awesome