I'm sort of not understanding your question, but I'll try to answer based on what I think you are saying.
You used boneless beef chuck for shredded beef, it was completely cooked in 3 hrs, but the recipe said it would take 9-11 hrs on high?
If I've got that right, then I'd probably say you didn't follow the recipe and should have allowed it to cook for the 9-11 hrs. Tough cuts of beef need long simmering times in a crock pot or oven, covered by liquids, to reach the point of easily shredding and being tender. When I make pot roast, which is easily shredded, in the crock pot I generally let it cook for at minimum 7 hrs on high, covered by liquid. Just because a meat is no longer pink doesn't mean it's "done" and tender.
Hope that helps. Not sure I answered your question.