Another Falklands/Malvinas war question..

Sorry if this should have gone onto the historic forum but……

For Christmas, I got the book “Razors Edge” by Hugh Bicheno. One of his most interesting comments concerns the use of the General Belgrano. He suggests that (page 109) the battleship should have been sailed into Port Stanley harbour before the UK task force arrived. Claiming that this is “probably the single act that could have tipped the scales against the British”, he points to the firepower of the 15-six inch and 8-five inch guns and also the twin radar directed 40mm AA guns.
This is the first time I had read of this idea and I wondered what your reactions are. How would the Harriers (presumably GR3s) be tasked with taking the Belgrano out of action? Would the Vulcans have had a chance of a hit? Is the author correct in assuming that all of the guns were actually serviceable? Were they acurate enough to represent a threat to individual frigates of the taskforce?

Look forward to your comments