Hi Folks!
Although Graf Spee and her sister ships were called pocket-battleships by the British, and although they carried six 11 inch guns, they are almost unable to fight real battleships. Their armor was only cruiser-style, after all, so the likeliest result when fighting Hood or Prince of Wales would be Invincible-style explosions...
The ships also never were meant to fight battleships. They should be faster than those, and escape (and this worked at least for most designs until about 1935), but be better armed than all faster ships, i.e. cruisers, which they were. Furthermore, these ships were a lot slower than Bismarck and Prinz Eugen. There are good reasons why neither Lützow nor Admiral Scheer were ever considered to join the two ships!
However, these ships were good commerce raiders because their Diesel engines gave them a lot of cruising range.
Actually, Graf Spee might have tried to escape (I think British secret services placed misleading information about battleships and carriers off the coast). I would have to look up how her status concerning speed and fuel was after the battle.
But I think that it would only have meant some psychological advantage for Germany, not much more. One commerce raider more or less could not win the war.
A much more interesting scenario is one in which Gneisenau and Scharnhorst are not damaged, and thus accompany Bismarck. Although only armed with 11-inchers as well, these ships had battleship armor...
SiKitu