The Best way I've found to heat corn totillas is to dip the corn shell completely under water (like what you do for rice wrappers for spring rolls), then place the wet shell on a hot cast iron skillet, cook 10 sec per side and stack. Repeat then Cover that stack with a dry cloth. As you know its traditional to use two corn tortilla wrappers per taco.
BTW, Next time try: smoking the meat to 140, then cover it with foil (Texas Crutch) and cook until internal temp is 190, then put in a cooler with a blanket for a nice little three hour nap to bring the meat down to 150--160.
Pull, pour and plate BABY!