Oh, ok, and if they release a comic in which Thor tries to lift a small rock and it's too heavy for him, is that a stated limit too? Give me a break. PIS should not be taken as examples. The fact is, Doc can alter matter at will, and he can multiply himself to an unknown and probably limitless amount of independent clones (as each clone can, in turn, multiply himself as well).
*facepalm* When it is the only limit he has ever had, it is not PIS! If movieManhattan did something more powerful that wiping out all nukes, then it is PIS. IIRC, he never did anything more powerful than that in the movie. Thus, it is not PIS!