Thanks
Interesting question.
Well if you look at how much damage 18 or so Royal Marines did on South Georgia, a couple of hundred Paras would probably have put a serious dent in the invasion plans. Whether it would have held up any reinforcements, who knows.
The problem would also have been one of re supply to the Paras once they were there as is always the case behind enemy lines.
I was thinking more of the deterrent effect of the Argies realising that the British would actively defend the place and calling the invasion off. However seeing that even if the RAF had still got the Belfast in service at the time, the aircraft could not have done the task required in the time scale required.