You had 2 butts at 7lbs and 7.5lbs. Both of those will cook anywhere between 6-10hrs depending on your temperatures. If you added another 3 more 7lb butts, it would still take the same amount of time to cook those. Now if it was just 1 big 14.5lb butt then yes, it would take more than 14hrs to cook it.
Also internal temperatures for pork butts are nothing more than a guide line. The saying "the meat is done when it is done" rings very true. 195F internal temp is when to start your bone wiggle test. If at 195F you wiggle the bone and it does not start to release, then the meat isnt done and let it go further. All pork butts finish differently, I have had one release the bone at 195F and another at 210F. Don't be afraid to see internal temperatures above 200F, pork butts are very forgiving and will remain moist and tender for a much greater temperature range than most meats.
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